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Background: Mucopolysaccharidosis II (MPS II) is an X-linked disorder resulting from a deficiency in lysosomal enzyme iduronate-2-sulfatase (IDS), which causes the accumulation of glycosaminoglycans (GAGs) in the lysosomes of many tissues and organs, leading to progressive cellular dysfunction. An MPS II newborn screening program has been available in Taiwan since 2015. The aim of the current study was to collect and analyze the long-term follow-up data of the screen-positive subjects in this program. Methods: From August 2015 to April 2022, 548,624 newborns were screened for MPS II by dried blood spots using tandem mass spectrometry, of which 202 suspected infants were referred to our hospital for confirmation. The diagnosis of MPS II was confirmed by IDS enzyme activity assay in leukocytes, quantitative determination of urinary GAGs by mass spectrometry, and identification of the IDS gene variant. Results: Among the 202 referred infants, 10 (5%) with seven IDS gene variants were diagnosed with confirmed MPS II (Group 1), 151 (75%) with nine IDS gene variants were classified as having suspected MPS II or pseudodeficiency (Group 2), and 41 (20%) with five IDS gene variants were classified as not having MPS II (Group 3). Long-term follow-up every 6 months was arranged for the infants in Group 1 and Group 2. Intravenous enzyme replacement therapy (ERT) was started in four patients at 1, 0.5, 0.4, and 0.5 years of age, respectively. Three patients also received hematopoietic stem cell transplantation (HSCT) at 1.5, 0.9, and 0.6 years of age, respectively. After ERT and/or HSCT, IDS enzyme activity and the quantity of urinary GAGs significantly improved in all of these patients compared with the baseline data. Conclusions: Because of the progressive nature of MPS II, early diagnosis via a newborn screening program and timely initiation of ERT and/or HSCT before the occurrence of irreversible organ damage may lead to better clinical outcomes. The findings of the current study could serve as baseline data for the analysis of the long-term effects of ERT and HSCT in these patients. [ABSTRACT FROM AUTHOR]

Background: Mucopolysaccharidoses (MPSs) are a group of inherited metabolic diseases, which are characterized by the accumulation of glycosaminoglycans, and eventually lead to the progressive damage of various tissues and organs.Methods: An epidemiological study of MPS in Taiwan was performed using multiple sources. The survival and diagnostic age for different types of MPS between 1985 and 2019 were evaluated.Results: Between 1985 and 2019, there were 175 patients diagnosed with MPS disorders in the Taiwanese population, with a median diagnostic age of 3.9 years. There were 21 (12%), 78 (45%), 33 (19%), 32 (18%) and 11 (6%) patients diagnosed with MPS I, II, III, IV and VI, respectively, with median diagnostic ages of 1.5, 3.8, 4.7, 4.5 and 3.7 years, respectively. Diagnosis of MPS patients was significantly earlier in recent decades (p < 0.01). Pilot newborn screening programs for MPS I, II, VI, IVA, and IIIB were progressively introduced in Taiwan from 2016, and 48% (16/33) of MPS patients diagnosed between 2016 and 2019 were diagnosed by one of these screening programs, with a median diagnostic age at 0.2 years. For patients born between 2016 and 2019, up to 94% (16/17) were diagnosed with MPS via the newborn screening programs. At the time of this study, 81 patients had passed away with a median age at death of 15.6 years. Age at diagnosis was positively correlated with life expectancy (p < 0.01). Life expectancy also significantly increased between 1985 and 2019, however this increase was gradual (p < 0.01).Conclusions: The life expectancy of Taiwanese patients with MPS has improved in recent decades and patients are being diagnosed earlier. Because of the progressive nature of the disease, early diagnosis by newborn screening programs and timely implementation of early therapeutic interventions may lead to better clinical outcomes. [ABSTRACT FROM AUTHOR]

Background: Patients with the later-onset IVS4+919G>A (IVS4) Fabry mutation are known to have positive central nervous system involvement compared with age- and sex-matched controls. This study compares central nervous system manifestations in patients with the IVS4 mutation or classical Fabry mutations.Methods: This was a retrospective analysis of magnetic resonance imaging (MRI) data from Taiwanese patients enrolled in the Fabry Outcome Survey (sponsored by Shire; data extracted March 2015).Results: Twenty-five IVS4 (19 males) and 12 (four males) classical Fabry patients underwent MRI at a median (range) age of 60.7 (45.0-70.4) and 43.0 (18.0-61.4) years, respectively. All patients received agalsidase alfa enzyme replacement therapy; two (16.7%) classical Fabry patients underwent MRI before treatment start. The pulvinar sign occurred in eight (32.0%; seven males) IVS4 and six (50.0%; three males) classical Fabry patients. Infarction occurred in eight (32.0%) IVS4 and four (33.3%) classical Fabry patients. Fazekas scores of 0, 1, 2, and 3 were found for 15 (60.0%), seven (28.0%), two (8.0%), and one (4.0%) of the IVS4 patients and for six (50.0%), four (33.3%), two (16.7%), and 0 classical Fabry patients, respectively. Abnormal height bifurcation of the basilar artery was observed in 40.0% of IVS4 and 58.3% of classical Fabry patients; abnormal laterality was observed in 4.0% of IVS4 and 16.7% of classical Fabry patients. Median (range) basilar artery diameter was 2.7 (1.4-4.0) mm in IVS4 and 3.2 (2.3-4.7) mm in classical Fabry patients (P = 0.0293); vascular stenosis was noted in 8.3% of IVS4 patients but in no classical Fabry patients.Conclusions: A similar range of MRI findings was found for both IVS4 and classical Fabry patients. Notably, basilar artery diameter was larger in classical Fabry patients than IVS4 patients. [ABSTRACT FROM AUTHOR]

Aim: Information regarding the functional strengths and weaknesses of children with Down syndrome is important for early intervention programmes and for agencies providing family support and educational services.Method: This study used the Functional Independence Measure for Children (WeeFIM) questionnaire for the parents or caregivers of 166 Taiwanese children (101 males and 65 females; median age 12y 7mo; range 3y 2mo-19y 1mo) with Down syndrome to assess their functional skills.Results: Out of a potential score of 126, the mean total WeeFIM score was 101.2. There was no statistically significant difference between the scores from the male and female participants (100.4 [SD 21.4] vs 102.4 [SD 24.7]; p>0.05). The mean scores for three domains (self-care, mobility, and cognition) were 45, 33, and 23 respectively (maximum of 56, 35, and 35 respectively). Performance was strongest in the mobility domain and weakest in the cognition domain. The total WeeFIM scores and 18 subscores for the three domains all positively correlated with age (p<0.05).Interpretation: For children with Down syndrome, some support and supervision is required for cognition and self-care tasks. The WeeFIM questionnaire may be useful for identifying the strengths and limitations of children with developmental disabilities and their families. [ABSTRACT FROM AUTHOR]

Background: Osteogenesis imperfecta (OI) is a congenital disorder characterized by increased bone fragility and low bone mass.Methods: The presence of COL1A1 or COL1A2 mutation was investigated by direct sequencing in 72 patients with OI type I, III, or IV (27 males and 45 females; age range 0.2-62 years) from 37 unrelated families. The clinical features of these patients were also recorded.Results: Thirty-seven COL1A1 and COL1A2 mutations were identified, including 28 COL1A1 mutations and 9 COL1A2 mutations. Fifteen (41%) were novel mutations, and twelve (32%) were familial mutations. A review of their medical records revealed that the 72 patients could be classified into OI type I (n = 42), III (n = 5), and IV (n = 25). Twenty-nine patients had helical mutations (caused by the substitution of a glycine within the Gly-X-Y triplet domain of the triple helix), and 42 had haploinsufficiency mutations (caused by frameshift, nonsense, and splice-site mutations). Compared with haploinsufficiency, the patients with helical mutations had more severely impaired skeletal phenotypes, including shorter height, lower bone mineral density, poorer walking ability, more frequent manifestations of dentinogenesis imperfecta and scoliosis (p < 0.05).Conclusions: Genotype and phenotype databases are expected to promote better genetic counseling and medical care of patients with OI. [ABSTRACT FROM AUTHOR]

Propionyl-CoA carboxylase (PCC) is involved in the catabolism of branched chain amino acids, odd-numbered fatty acids, cholesterol, and other metabolites. PCC consists of two subunits, α and β, encoded by the PCCA and PCCB genes, respectively. Mutations in the PCCA or PCCB subunit gene may lead to propionic acidemia. In this study, we performed mutation analysis on ten propionic acidemia patients from eight unrelated and nonconsanguineous families in Taiwan. Two PCCA mutations, c.229C→T (p.R77W) and c.1262A→C (p.Q421P), were identified in a PCCA-deficient patient. Six mutations in the PCCB gene, including c.-4156_183+3713del, c.580T→C (p.S194P), c.838dup (p.L280Pfs*11), c.1301C→T (p.A434V), c.1316A→G (P.Y439C), and c.1534C→T (p.R512C), were identified in seven PCCB-deficient families. The c.-4156_183+3713del mutation is the first known large deletion that affects the PCCB gene functions. Furthermore, the c.1301C→T and c.-4156_183+3713del mutations in the PCCB gene have not been reported previously. Clinical features demonstrated that these two frequent mutations are associated with low enzyme activity and a classic propionic acidemia phenotype. [ABSTRACT FROM AUTHOR]

Aim. To extend nursing knowledge of distress experienced by family caregivers of children with rare genetic disorders, by exploring the perspectives of caregivers of children with Russell-Silver Syndrome in Taiwan. Background. Caring for a child with a rare genetic disorder often has profound effects on families, especially when diagnosis and treatment is complex or not yet well developed, such as that in Russell-Silver Syndrome (or Silver-Russell syndrome). This disorder causes dwarfism and developmental difficulties, requiring long-term care planning. Previous research has focused mostly on medical care, but little is known about families' perspectives of caring difficulties, the help they need and nursing care required. Design. An exploratory qualitative approach was used to inform this study. Methods. Family caregivers, whose children were undergoing medical care in a leading Taiwan medical centre, were invited to participate in face-to-face, in-depth interviews. Data were analysed by content analysis. Results. Fifteen caregivers including 11 mothers, two fathers and two grandmothers participated. Five major themes and 13 sub-themes of care-giving distress were identified: endless psychological worries; the lengthy process to confirm a medical diagnosis; adjustment efforts in modifying family roles; dilemmas in deciding between Western or Chinese traditional medicine; and negative responses to society's concerns. Their primary sources of support were spouses, parents and health professionals, accordingly. Conclusion. Complex physio-psycho-social and decision-making distress in caring for children with a rare genetic disorder were systematically revealed from the perspectives of ethnic-Chinese family caregivers. Relevance to clinical practice. Long-term care plans for children with a rare genetic disorder such as Russell-Silver Syndrome need to focus on positive dynamic family interactions, life-stage development and family caregiver support. Research on care-giving in rare genetic disorders is also warranted across cultures and countries to develop a substantial knowledge basis for nursing practice. [ABSTRACT FROM AUTHOR]

Abstract: 6-Pyruvoyl-tetrahydropterin synthase (PTPS) deficiency is the most frequent form of tetrahydrobiopterin (BH4) deficiency related to hyperphenylalaninemia (HPA). PTPS deficiency may not only cause a typical phenylketonuric phenotype, but is also accompanied by various neurological signs and symptoms due to impaired synthesis of catecholamines and serotonin. The treatment of PTPS deficiency is aimed at normalizing phenylalanine levels and brain neurotransmitters. The BH4 can be administered to normalize phenylalanine (PHE) levels easily, but, owing to severe side effects, the neurotransmitters, l-DOPA and 5-hydroxytryptophan, should be administered for these patients very carefully. However, optimal dosage of the neurotransmitters for PTPS deficiency patients is difficult to be determined. Several reports have described unsatisfied outcomes in a large percentage of patients with PTPS deficiency, despite early detection and treatment. Between 1988 and 2000, 12 newborns with PTPS deficiency identified by newborn screening were referred and received early treatment at our hospital. The mean IQ score of these 12 patients was 96.7 (±9.7; range: 86–119), which is considerably higher than previous reports of other populations of PTPS-deficient patients. In this report, we reviewed the disorders of BH4 briefly and then described treatments of our PTPS-deficient patients. [Copyright &y& Elsevier]

Background: The clinical course of methylmalonic aciduria (MMA) is fulminant in neonates and emergency management is necessary to save lives. It is therefore very important to differentiate affected from unaffected neonates immediately when there are abnormal results regarding MMA in newborn screening. Methods: Between January 2002 and December 2008, 598,522 newborns were screened for MMA by 2 neonatal screening centers: the Chinese Foundation of Health and the Taipei Institute of Pathology. A total of 22 newborns were referred to confirmatory medical centers, and 7 were confirmed as having MMA. The initial propionylcarnitine (C3) level, C3/acetylcarnitine (C2) ratio, plasma ammonia, liver function tests, blood pH and bicarbonate were compared between the true-positive and false-positive groups. Results: The C3/C2 ratio and plasma ammonia were markedly higher in the true-positive MMA group (p < 0.0001). Blood gas pH (p = 0.029), bicarbonate (p = 0.019), and aspartate aminotransferase (p = 0.005) also significantly differed between these 2 groups. Conclusion: Referred newborns with elevated plasma C3/C2 ratios > 0.4 or ammonia levels > 200 mg/dL should be highly suspected of having MMA. [Copyright &y& Elsevier]

The article presents a study on the diagnosis of the cardiac variant of the Fabry disease through newborn screening. Disease incidence were ascertained in the Taiwan Chinese population using the newborn screening program based on the assessment of the enzyme activity. Results show that Fabry mutations among newborns were high, highlighting the importance of early detection to allow therapeutic intervention with enzyme replacement therapy.

Background/purpose: Osteogenesis imperfecta (OI) (MIM 166200, 166210, 259420 and 166220) is a congenital disorder characterized by increased bone fragility and low bone mass. Information regarding the clinical features of this genetic disorder is lacking in Taiwan. This study aimed to characterize the clinical features of OI patients in Taiwan to establish a practical correlation for distinguishing different clinical subtypes of the disorder.Methods: A review of medical records identified 48 patients with OI (33 female and 15 male; age range, 2 months to 53 years) from January 1996 to June 2008. Diagnosis and classification, using the classification system outlined by Sillence et al, were based on clinical and radiological characteristics. We also analyzed the clinical presentation, physical examination and bone mineral density (BMD) among the different subtypes of OI.Results: Retrospective analysis of the medical records revealed that 48 OI patients could be classified into types I (n = 19), III (n = 10), and IV (n = 19). There were statistically significant differences between these three types in terms of height, weight, BMD, dentinogenesis imperfecta, bone deformity, scoliosis, walking ability, annual fracture rate, and family history. However, no significant differences were noted for blue sclera (p = 0.075) and hearing loss (p = 0.832).Conclusion: Nine of the 11 clinical features examined---height, weight, BMD, dentinogenesis imperfecta, bone deformity, scoliosis, walking ability, fracture rate, and family history---were significantly different among the three types of OI patients. This finding may be of help in evaluating patients and establishing their prognosis. [ABSTRACT FROM AUTHOR]

Background: Silver–Russell syndrome (SRS) is a clinically and genetically heterogeneous disorder characterized by severe intrauterine growth retardation, poor postnatal growth, characteristic facial features, and body asymmetry. Hypomethylation of the imprinted genes of the chromosome 11p15.5 imprinting gene cluster and maternal uniparental disomy of chromosome 7 (mUPD7) are the major epigenetic disturbances. The aim of this study was to characterize the epigenotype, genotype, and phenotype of these patients in Taiwan. Methods: Two hundred and six subjects with clinically suspected SRS were referred for diagnostic testing, which was performed by profiling the methylation of H19-associated imprinting center (IC) 1 and the imprinted PEG1/MEST region using methylation-specific multiplex ligation-dependent probe amplification and high-resolution melting analysis with a methylation-specific polymerase chain reaction assay. We also applied a whole genome strategy to detect copy number changes and loss of heterozygosity. Clinical manifestations were recorded and analyzed according to the SRS scoring system proposed by Bartholdi et al. Results: Among the 206 referred subjects, 100 were classified as having a clinical diagnosis of SRS (score ≥ 8, maximum = 15) and 106 had an SRS score ≤ 7. Molecular lesions were detected in 45% (45/100) of the subjects with a clinical diagnosis of SRS, compared to 5% (5/106) of those with an SRS score ≤ 7. Thirty-seven subjects had IC1 hypomethylation, ten subjects had mUPD7, and three subjects had microdeletions. Several clinical features were found to be statistically different (p < 0.05) between the "IC1 hypomethylation" and "mUPD7" groups, including relative macrocephaly at birth (89% vs. 50%), triangular shaped face (89% vs. 50%), clinodactyly of the fifth finger (68% vs. 20%), and SRS score (11.4 ± 2.2 vs. 8.3 ± 2.5). Conclusions: The SRS score was positively correlated with the molecular diagnosis rate (p < 0.001). The SRS subjects with mUPD7 seemed to have fewer typical features and lower SRS scores than those with IC1 hypomethylation. Careful clinical observation and timely molecular confirmation are important to allow for an early diagnosis and multidisciplinary management of these patients. [ABSTRACT FROM AUTHOR]

Congenital insensitivity to pain with anhidrosis (CIPA) is characterized by insensitivity to pain, anhidrosis, recurrent hyperpyrexia, mild mental retardation, and self-mutilating behavior. We report 2 brothers, aged 20 and 18 years, who suffered from phenotypes of CIPA. Both brothers had a branch site mutation in intron 7 (IVS7-33 T→A) of the neurotrophic tyrosine kinase receptor type 1 gene. The electrophysiological studies showed no significant abnormal findings in sensory evoked potentials, motor evoked potentials to transcranial magnetic stimulation, or heart rate variations; sympathetic skin responses were absent. Morphometric study of their sural nerve histopathology revealed normal myelinated fiber density, 8,082 fibers/mm2 and 5,637 fibers/mm2 (normal 6,141 ± 421); decreased unmyelinated fiber density, 2,537 fibers/mm2 and 2,211 fibers/mm2 (normal 28,578 ± 8,669); increased axon size, 4.41 ± 1.59 μm and 5.33 ± 1.48 μm (normal 3.73 ± 1.45), and increased axon diameter (A)/myelin thickness (M) ratio (A/M), 3.47 ± 1.42 and 2.70 ± 1.07 (normal 2.49 ± 0.93). Scatterplot analysis of the G ratio (axon diameter:fiber diameter) did not show consistent results in the relationship between axon size and myelin thickness. In conclusion, the neuropathy of our CIPA patients included a marked reduction of small myelinated and unmyelinated fibers and a relatively increased axon size. This is the first CIPA family encountered in Taiwan. Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Children with mucopolysaccharidosis (MPS) generally appear unaffected at birth but may develop multiple clinical manifestations including profound growth impairment as they grow older. Each type of MPS has a variable age at onset and variable rate of progression, however, information regarding growth in Asian children is limited. Methods: This retrospective analysis included 129 Taiwanese patients with MPS (age range, 0.7 to 19.5 years, median age, 7.9 years) from eight medical centers in Taiwan from January 1996 through December 2018. Results: The mean z scores for the first recorded values of height, weight, and body mass index in the patients' medical records were −4.25, −1.04, and 0.41 for MPS I (n = 9), −2.31, 0.19, and 0.84 for MPS II (n = 49), −0.42, 0.08, and −0.12 for MPS III (n = 27), −6.02, −2.04, and 0.12 for MPS IVA (n = 30), and −4.46, −1.52, and 0.19 for MPS VI (n = 14), respectively. MPS IVA had the lowest mean z scores for both height and weight among all types of MPS, followed by MPS VI, MPS I, MPS II, and MPS III, which showed the mildest growth retardation. Both z scores for height and weight were negatively correlated with increasing age for all types of MPS (p < 0.01). Of 32 patients younger than 5 years of age, 16 (50%), and 23 (72%) had positive z scores of height and weight, respectively. A substantial number of younger patients with MPS I, II, III, and IVA had a positive height z score. The median age at diagnosis was 3.9 years (n = 115). Conclusions: The patients with MPS IVA had the most significant growth retardation among all types of MPS, followed by MPS VI, MPS I, MPS II, and MPS III. The height and weight of the MPS patients younger than 2–5 years of age were higher than those of healthy individuals, however, their growth significantly decelerated in subsequent years. Understanding the growth curve and potential involved in each type of MPS may allow for early diagnosis and timely management of the disease, which may improve the quality of life. [ABSTRACT FROM AUTHOR]

Background: The mucopolysaccharidoses (MPSs) are a group of rare lysosomal storage disorders characterized by the accumulation of glycosaminoglycans (GAGs) and which eventually cause progressive damage to various tissues and organs. We developed a feasible MPS screening algorithm and established a cross-specialty collaboration platform between medical geneticists and other medical specialists based on at-risk criteria to allow for an earlier confirmative diagnosis of MPS. Methods: Children (<19 years of age) with clinical signs and symptoms compatible with MPS were prospectively enrolled from pediatric clinics between July 2013 and June 2018. Urine samples were collected for a non-specific total GAG analysis using the dimethylmethylene blue (DMB) spectrophotometric method, and the quantitation of three urinary GAGs (dermatan sulfate (DS), heparan sulfate (HS), and keratan sulfate (KS)) was performed by liquid chromatography/tandem mass spectrometry (LC-MS/MS). The subjects with elevated urinary GAG levels were recalled for leukocyte enzyme activity assay and genetic testing for confirmation. Results: Among 153 subjects enrolled in this study, 13 had a confirmative diagnosis of MPS (age range, 0.6 to 10.9 years—three with MPS I, four with MPS II, five with MPS IIIB, and one with MPS IVA). The major signs and symptoms with regards to different systems recorded by pediatricians at the time of the decision to test for MPS were the musculoskeletal system (55%), followed by the neurological system (45%) and coarse facial features (39%). For these 13 patients, the median age at the diagnosis of MPS was 2.9 years. The false negative rate of urinary DMB ratio using the dye-based method for these 13 patients was 31%, including one MPS I, two MPS IIIB, and one MPS IVA. However, there were no false negative results with urinary DS, HS and KS using the MS/MS-based method. Conclusions: We established an at-risk population screening program for MPS by measuring urinary GAG fractionation biomarkers using the LC-MS/MS method. The program included medical geneticists and other medical specialists to increase awareness and enable an early diagnosis by detecting MPS at the initial onset of clinical symptoms. [ABSTRACT FROM AUTHOR]

Background: Information on functional strengths and weaknesses of mucopolysaccharidosis (MPS) patients is important for early intervention programs and enzyme replacement therapy (ERT). Methods: We used the Functional Independence Measure for Children (WeeFIM) questionnaire to assess the functional skills of 63 Taiwanese MPS patients (median age, 13 years 3 months; range, 3–20 years) from January 2012 to December 2018. Results: Mean total WeeFIM score was 75.4 of a potential score of 126. Mean total WeeFIM scores of each type (MPS I, MPS II, MPS IIIB, MPS IVA, and MPS VI) were 103.8, 76.2, 41.6, 92.2, and 113.6, respectively. Mean scores for self‐care, mobility, and cognition domains were 30 (maximum 56), 23 (maximum 35), and 22 (maximum 35), respectively. MPS type IIIB patients had the lowest scores in self‐care, mobility, cognition, and total domains compared to other types of MPS. All patients with ERT in MPS I, II, and IVA had higher scores in self‐care and mobility domains than patients without ERT. Most patients required assistance for self‐care skills, especially in grooming and bathing. Conclusion: MPS patients require support and supervision in self‐care tasks. For cognition tasks, MPS IIIB patients also require help. This questionnaire is useful to identify the strengths and limitations of MPS patients. [ABSTRACT FROM AUTHOR]

Background: Cardiac abnormalities have been observed in patients with mucopolysaccharidosis (MPS) of any type, with the most documented abnormalities being valvular heart disease and cardiac hypertrophy. However, few studies have focused on the cardiac features of MPS IVA.Methods: We reviewed the medical records, echocardiograms, and electrocardiograms of 32 Taiwanese patients with MPS IVA (16 males and 16 females; median age, 10.8 years; age range, 1.1 to 29.1 years) as well as the echocardiographic data of six patients who received enzyme replacement therapy (ERT) for 3-6 years.Results: Echocardiographic examinations (n = 32) revealed mean z scores of left ventricular mass index (LVMI), interventricular septum diameter in diastole (IVSd), left ventricular posterior wall diameter in diastole (LVPWd), and aortic diameter of 0.94, 2.70, 0.39, and 3.26, respectively. Z scores > 2 were identified in 25%, 50%, 29%, and 69% of the LVMI, IVSd, LVPWd, and aortic diameter values, respectively. Diastolic dysfunction [reversed ratio between early and late (atrial) ventricular filling velocity (E/A ratio < 1)] was identified in four patients (13%), however, the ejection fraction was normal (50-75%) in all of the patients. Sixteen patients (50%) had valvular heart disease and most were of mild degree. Fourteen (44%) had valvular stenosis, and 10 (31%) had regurgitation. The z scores of LVMI, IVSd, LVPWd, and aortic diameter, the severity scores of aortic stenosis and regurgitation, and the existence of a thickened interventricular septum were all positively correlated with increasing age (p < 0.05). For the 14 patients with valve thickening, the z scores of LVMI, IVSd and aortic diameter were all larger than those of the 18 patients without valve thickening (p < 0.05). For two patients who started ERT at a younger age (1.4 and 2.8 years, respectively), the z scores for LVMI, IVSd, and LVPWd all decreased after ERT.Conclusions: A large proportion of the patients with MPS IVA had valvular heart disease and cardiac hypertrophy. Cardiac abnormalities worsened with increasing age in accordance with the progressive nature of this disease. ERT appeared to be effective in stabilizing or reducing cardiac hypertrophy, and better results may have been associated with starting ERT at a younger age. [ABSTRACT FROM AUTHOR]

Abstract: Background: Interest in lysosomal storage diseases in newborn screening programs has increased in recent years. Two techniques, fluorescence (4-MU) and tandem mass spectrometry (MS/MS) methods are frequently used. We report a pilot study of large scale newborn screening for Fabry, Pompe, Gaucher, and MPS I diseases by using the MS/MS method in Taiwan and compared the performance of the MS/MS with 4-MU methods. Methods: More than 100,000 dried blood spots (DBSs) were collected consecutively as part of the national Taiwan newborn screening programs. The enzyme activities were detected by the MS/MS method from a DBS punch. Mutation analysis was further performed for newborns with detected enzyme deficiency. Results: The DNA sequence analysis for suspected cases revealed 64 newborns with confirmed Fabry mutations, 16 were classified as infantile or late-onset Pompe disease, and 1 was characterized as Gaucher disease. The positive predict value increased from 4.0% to 7.1% in the Pompe study, and from 61.0% to 95.5% in the Fabry study by the MS/MS method compared to 4-MU assay. Conclusions: The MS/MS method has been validated as a more specific, powerful and efficient tool than the 4-MU assay. It also provided a multiplex solution of newborn screening for lysosomal storage diseases. [Copyright &y& Elsevier]

Abstract: The newborn screening of homocystinuria in Taiwan has never been formally reported before. Since 1984, out of 5million newborns screened, only 3 newborns (Han Taiwanese) suffering from homocystinuria were detected in this newborn screening program. Four mutations (p.R121L [c.362G>T], p.E176K [c.526G>A], p.V320G [c.959T>G] and p.G259D [c.776G>A]) were identified in these 3 patients. Unexpectedly, we recently found 8 patients presenting with homocystinuria in an Austronesian Taiwanese Tao tribe. Out of them, three patients participated in the newborn screening program but were unidentified by the current newborn homocystinuria (using methionine as a marker) screening. All the Tao patients are homozygous for a new p.D47E (c.141T>A) mutation. Among the 428 adult islanders screened for the D47E mutation, approximately 1 in 7.78 is a carrier of the mutation, and an estimated 1 in 240 islanders suffered from homocystinuria. This is the highest known prevalence of homocystinuria worldwide. The result of expression studies of all the mutations identified in Taiwan revealed that, except for p.D47E mutation, all mutations were severely limited in their ability to form functional tetramers. The clinical manifestations of the Tao patients varied widely, despite sharing the same mutation and very similar genetic and environmental backgrounds. Comparisons of clinical and biochemical phenotypes of these patients were presented in this report. [Copyright &y& Elsevier]

The Fabry disease-causing mutation, the GLA IVS4+919G>A (designated GLA IVS4), is very prevalent in patients with hypertrophic cardiomyopathy in Taiwan. This X-linked mutation has also been found in patients in Kyushu, Japan and Southeast Asia. To investigate the age and the possible ancestral origin of this mutation, a total of 33 male patients with the GLA IVS4+919G>A mutation, born in Taiwan, Japan, Singapore, Malaysia, Vietnam, and the Fujian and Guangdong provinces of China, were studied. Peripheral bloods were collected, and the Ilumina Infinium CoreExome-24 microarray was used for dense genotyping. A mutation-carrying haplotype was discovered which was shared by all 33 patients. This haplotype does not exist in 15 healthy persons without the mutation. Rather, a wide diversity of haplotypes was found in the vicinity of the mutation site, supporting the existence of a single founder of the GLA IVS4 mutation. The age of the founder mutation was estimated by the lengths of the mutation-carrying haplotypes based on the linkage-disequilibrium decay theory. The first, second, and third quartile of the age estimates are 800.7, 922.6, and 1068.4 years, respectively. We concluded that the GLA IVS4+919G>A mutation originated from a single mutational event that occurred in a Chinese chromosome more than 800 years ago.

Background: Mucopolysaccharidoses (MPSs) are a group of rare lysosomal storage disorders characterized by the accumulation of glycosaminoglycans in various tissues and organs. Ocular problems that affect the cornea, trabecular meshwork, sclera, retina, and optic nerve are very common in these patients. However, there was limited literature focusing on comprehensive ocular findings in different types of MPS., Methods: We retrospectively reviewed the clinical ophthalmologic features and electrodiagnostic results of 50 Taiwanese patients with a diagnosis of MPS (34 males and 16 females; age range, 1.1-34.9 years; nine with MPS I, 17 with MPS II, 17 with MPS IV, and seven with MPS VI)., Results: Among 44 patients with available data for visual acuity, 15 patients (34%) had a visual acuity of less than 0.5 (6/12) equivalent in their better eye, including 71% of those with MPS VI, 38% with MPS IV, 29% with MPS I, and 14% with MPS II. Severe corneal opacities existed in 57% of MPS VI patients and 11% of MPS I patients, compared with none for MPS II and MPS IV patients. Among 80 eyes with available data of refraction, 11 eyes (14%) had myopia (≦-0.50 D), 55 eyes (69%) had hyperopia (≧0.50 D), and 55 eyes (69%) had high astigmatism (≧1.50 D). Ocular hypertension was found in 45% (28/62) of eyes. There were 16% (14/90), 11% (10/90), 13% (12/90), 31% (27/86), and 79% (30/38) of MPS eyes with lens opacities, optic disc swelling, optic disc cupped, retinopathy, and visual pathway dysfunction, respectively. Intraocular pressure was positively correlated with the severity of corneal opacity (p < 0.01)., Conclusions: Ocular complications with significant reduction in visual acuity are common in MPS patients. Diagnostic problems may arise in these patients with severe corneal opacification, especially for those with MPS VI and MPS I., (© 2019 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.)

Background: Most patients with isolated methylmalonic acidemia (MMA) /propionic acidemia (PA) presenting during the neonatal period with acute metabolic distress are at risk for death and significant neurodevelopmental disability. The nationwide newborn screening for MMA/PA has been in place in Taiwan from January, 2000 and data was collected until December, 2016., Results: During the study period, 3,155,263 newborns were screened. The overall incidence of MMA mutase type cases was 1/121,356 (n = 26), 1 cobalamin B was detected and that for PA cases (n = 4) was 1/788,816. The time of referral is 8.8 days for MMA patients, and 7.5 days for PA patients. The MMA mutase type patients have higher AST, ALT, and NH 3 values as well as a lower pH value (p < 0.05). The mean age for liver transplantation (LT) is 402 days (range from 0.6-6.7 yr) with 16 out of 20 cases (80.0%) using living donors. The mean admission length shortened from 90.6 days/year (pre-LT) to 5.3 days/year (at 3rd year post-LT) (p < 0.0005). Similarly, the tube feeding ratio decreased from 67.8 to 0.50% (p < 0.00005). The anxiety level of the caregiver was reduced from 33.4 to 27.2 after LT (p = 0.001) and the DQ/IQ performance of the patients was improved after LT from 50 to 60.1 (p = 0.07)., Conclusion: MMA/PA patients with LT do survive and have reduced admission time, reduced tube feeding and the caregiver is less anxious.

Mucopolysaccharidosis type III (MPS III, Sanfilippo syndrome) has a variable age of onset and variable rate of progression. However, information regarding the natural history of this disorder in Asian populations is limited. A retrospective analysis was carried out for 28 patients with MPS III (types IIIA [n = 3], IIIB [n = 23], and IIIC [n = 2]; 15 males and 13 females; median age, 8.2 years; age range, 2.7-26.5 years) seen in six medical centers in Taiwan from January 1996 through October 2017. The median age at confirmed diagnosis was 4.6 years. The most common initial symptom was speech delay (75%), followed by hirsutism (64%) and hyperactivity (54%). Both z scores for height and weight were negatively correlated with age (r = -.693 and -0.718, respectively; p < .01). The most prevalent clinical manifestations were speech delay (100%) and intellectual disability (100%), followed by hirsutism (93%), hyperactivity (79%), coarse facial features (68%), sleep disorders (61%), and hepatosplenomegaly (61%). Ten patients (36%) had epilepsy, and the median age at the first seizure was 11 years. Thirteen patients (46%) experienced at least one surgical procedure. At the time of the present study, 7 of the 28 patients had passed away at the median age of 13.0 years. Molecular studies showed an allelic heterogeneity without clear genotype and phenotype correlations. MPS IIIB is the most frequent subtype among MPS III in the Taiwanese population. An understanding of the natural history of MPS III may allow early diagnosis and timely management of the disease facilitating better treatment outcomes., (© 2018 Wiley Periodicals, Inc.)

Background: Mucopolysaccharidosis type II (MPS II) is the most frequently occurring MPS in Taiwan, with an incidence of 2.05 per 100,000 live male births, but little is known about clinical characteristics and surgical history in Taiwanese patients., Methods: Medical history, demographics, signs and symptoms, and surgical history were analysed in all patients from Taiwanese centres in the Hunter Outcome Survey (HOS; NCT 03292887), a global, multicentre registry that collects real-world data on patients with MPS II., Results: As of January 2016, 61 male Taiwanese patients were enrolled; 49% (24/49) had received at least one infusion of idursulfase. Median (10th, 90th percentiles) ages at signs and symptom onset and at diagnosis were 2.5 (0.2, 5.5) years (n = 55) and 3.5 (1.2, 11.9) years (n = 56), respectively. Hernia, facial features consistent with MPS II and claw hands were the earliest presenting signs and symptoms (median ages of 3.2 [0.4, 12.0] years, 4.3 [1.1, 12.0] years and 4.7 [2.5, 12.2] years [n = 45, 53 and 50], respectively). More than 75% of patients had undergone a surgical procedure, most commonly hernia repair (57% of patients). Median age at first surgery for hernia repair was 4.2 (0.5, 9.8) years (n = 35). Almost one-third (31.1%) of patients had at least one surgical procedure before diagnosis, and of the 20 procedures before diagnosis, 16 were hernia repair., Conclusions: This information from patients in HOS highlights the importance of both medical and surgical history in diagnosing MPS II in Taiwanese patients.

Prader-Willi syndrome (PWS) is a genetic disorder with obesity, developmental delay, short stature, and behavioral abnormalities. The study aimed to assess the functional independence in children with PWS. The Functional Independence Measure for Children (WeeFIM) was used to evaluate 81 children with PWS (44 boys and 37 girls) with a median age of 11 years 1 month (range 2 years 8 months to 20 years 2 months) were recruited between January 2013 and December 2016. The mean total WeeFIM score was 103.8 (maximum 126). Sixty-five patients (80%) had deletion type PWS, 16 (20.0%) had nondeletion type. The scores were 103.6 ± 18.5 for deletion and 104.8 ± 18.3 for nondeletion type (p = .405), 104.8 ± 19.3 in boys and 102.6 ± 17.3 in girls (p = .293). The mean self-care, mobility, and cognition scores were 47 (maximum 56), 33 (maximum 35), and 24 (maximum 35), respectively. All total scores and 18 subscores in the three functional domains were positively correlated with age (p < .05). Most children required assistance in problem-solving, comprehension, and expression. The WeeFIM identified the strengths and limitations of children with PWS and confirmed that support and supervision were needed in cognitive and self-care tasks., (© 2018 Wiley Periodicals, Inc.)

Fabry disease is an X-linked disorder resulted from deficiency of α-galactosidase A (GLA) activity. In Taiwan, a total of 792,247 newborns were screened from 2008 to 2014 in two newborn screening centers, and 13 variants of uncertain significance (VOUS) in the GLA gene were identified. To determine whether these variants were pathogenic or not, functional, biochemical, clinical and pedigree analyses were performed. In vitro functional assay was established through site-directed mutagenesis, and four in silico tools were used to predict pathogenesis. The enzyme activity of dried blood spots and plasma metabolite lyso-Gb3 level from subjects with the variants were measured. Additionally, clinical manifestations were evaluated extensively from the subjects and their relatives. Our results revealed that p.G104V, p.I232T, p.D322H, and p.G360C all exhibited relatively low residual enzyme activities and elevated plasma lyso-Gb3 level. These data strongly suggest that these Fabry mutations may cause classical or later-onset phenotypes. In contrast, neither significantly clinical symptoms nor elevated lyso-Gb3 level was found in cases with p.P60S, p.A108T, p.S304T, p.R356Q, and p.P362T variants, which may be non-pathogenic or milder forms of Fabry variants. More data need to be included for the patients with p.N53D, p.P210S, p.M296L, and p.K391T variants. The established system provides us more information to classify these GLA variants., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Recently, several studies revealed a much higher prevalence of later onset Fabry disease (FD) than previously expected. It suggested that later onset FD might present as an important hidden health issue in certain ethnic or demographic populations in the world. However, the natural history of its phenotype has not been systemically investigated, especially the cardiac involvement., Objectives: The study analyzed a large-scale newborn screening program for FD to understand the natural course of later onset FD., Methods: To date, 916,383 newborns have been screened for FD in Taiwan, including more than 1,200 individuals with the common, later onset IVS4+919G>A (IVS4) mutation. Echocardiography was performed in 620 adults with the IVS4 mutation to analyze the prevalence of left ventricular hypertrophy (LVH), and gadolinium-enhanced cardiac magnetic resonance imaging was performed in 129 patients with FD, including 100 IVS4 adults., Results: LVH was observed in 67% of men and 32% of women older than 40 years. Imaging evidenced significant late gadolinium enhancement in 38.1% of IVS4 men and 16.7% of IVS4 women with the IVS4 mutation but without LVH. Seventeen patients underwent endomyocardial biopsies, which revealed significant globotriaosylceramide substrate accumulation in their cardiomyocytes., Conclusions: Significant cardiomyocyte substrate accumulation in IVS4 patients led to severe and irreversible cardiac fibrosis before development of LVH or other significant cardiac manifestations. Thus, it might be too late to start enzyme replacement therapy after the occurrence of LVH or other significant cardiac manifestations in patients with later onset FD. This study also indicated the importance of newborn screening for early detection of the insidious, ongoing, irreversible cardiac damage in patients with later onset FD., (Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Osteogenesis imperfecta (OI) is a congenital disorder characterized by increased bone fragility and low bone mass., Methods: The presence of COL1A1 or COL1A2 mutation was investigated by direct sequencing in 72 patients with OI type I, III, or IV (27 males and 45 females; age range 0.2-62 years) from 37 unrelated families. The clinical features of these patients were also recorded., Results: Thirty-seven COL1A1 and COL1A2 mutations were identified, including 28 COL1A1 mutations and 9 COL1A2 mutations. Fifteen (41%) were novel mutations, and twelve (32%) were familial mutations. A review of their medical records revealed that the 72 patients could be classified into OI type I (n = 42), III (n = 5), and IV (n = 25). Twenty-nine patients had helical mutations (caused by the substitution of a glycine within the Gly-X-Y triplet domain of the triple helix), and 42 had haploinsufficiency mutations (caused by frameshift, nonsense, and splice-site mutations). Compared with haploinsufficiency, the patients with helical mutations had more severely impaired skeletal phenotypes, including shorter height, lower bone mineral density, poorer walking ability, more frequent manifestations of dentinogenesis imperfecta and scoliosis (p < 0.05)., Conclusions: Genotype and phenotype databases are expected to promote better genetic counseling and medical care of patients with OI.

Background & Aims: Many studies have reported that serum total homocysteine (tHcy) levels in cystathionine-beta-synthase (CBS) carriers are usually normal and only elevated after a methionine load. However, the amount of methionine required for a loading test is non-physiological and is never reached with regular feeding. Therefore, CBS carriers do not seem to be at an increased risk of cardiovascular diseases. However, the risk of cardiovascular diseases of CBS carriers with folate deficiency has not been studied. We recently found an extraordinarily high carrier rate (1/7.78) of a novel CBS mutation (p.D47E, c.T141A) in an Austronesian Taiwanese Tao tribe who live in a geographic area with folate deficiency. We evaluated if the CBS carriers tend to have higher fasting serum tHcy concentrations than non-carriers in presence of folate deficiency., Methods: The serum tHcy and folate levels before and after folate replacement were measured in 48 adult Tao carriers, 40 age-matched Tao non-carriers and 40 age-matched Han Taiwanese controls., Results: The serum tHcy level of the Tao CBS carriers (17.9 ± 3.8 μmol/l) was significantly higher than in Tao non-carriers (15.7 ± 3.5 μmol/l; p < 0.008) and Taiwanese controls (11.8 ± 2.9 μmol/l; p < 0.001). Furthermore, a high prevalence of folate deficiency in the Tao compared with the Taiwanese controls (4.9 ± 1.8 ng/ml vs. 10.6 ± 5.5 ng/ml; p < 0.001) was also noted. Of note, the difference in tHcy levels between the carriers and non-carriers was eliminated by folate supplementation. (carriers:13.65 ± 2.13 μmol/l; non-carriers:12.39 ± 3.25 μmol/l, p = 0.321)., Conclusions: CBS carriers tend to have a higher tHcy level in the presence of folate deficiency than non-carriers. Although many reports have indicated that CBS carriers are not associated with cardiovascular disease, the risk for CBS carriers with folate deficiency has not been well studied. Owing to a significantly elevated level of fasting tHcy without methionine loading, it is important to evaluate the risk of cardiovascular disease in CBS carriers with folate deficiency., (Copyright © 2014 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

Background: In view of the therapeutic benefits resulting from early intervention for Fabry disease, our team has implemented an enzyme-based newborn screening in Taiwan since 2008. However, we found that most heterozygous females cannot be detected. To improve the screening efficiency, a more effective method for GLA gene genotyping is necessary., Methods: As the suspected mutations are limited to only 29 different spots in Taiwanese, a panel of Sequenom iPLEX assay was designed for rapid screening of GLA variations. To determine the accuracy and sensitivity of this assay, previously diagnosed and undiagnosed DNA samples were analyzed by this genotyping assay and Sanger sequencing. In addition, DNA extracted from dried blood spots was also tested., Results: Sequenom iPLEX assay is accurate and cost-effective, identifying the sequence variations, which were designated in the panel. It identified common GLA variants in DNA samples extracted from whole blood or dried blood spots with 100% accuracy and sensitivity., Conclusions: Sequenom iPLEX assay is suitable for Fabry newborn screening when hotspot mutations and common variations are known in a well-studied population. In addition, this assay can also be applied for first-line determination of GLA variant sequences in suspected subjects of high-risk patients, or newborns., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Phenylalanine hydroxylase (PAH) deficiency is responsible for most cases of phenylketonuria (PKU). In this study of the PAH mutation spectrum in the Taiwanese population, 139 alleles were identified including 34 different mutations. The V190G, Q267R and F392I mutations are first reported in this study. The most common mutations, R241C, R408Q and Ex6-96A>G, account for 23.2%, 12.0% and 9.2%, of the mutant alleles, respectively. Haplotype analysis shows that R241C and Ex6-96A>G are exclusively associated with haplotype 4.3 to suggest founder effects. On the other hand, R408Q is found on two distinct haplotypes suggesting recurrent mutations. The spectrum of PAH mutations in Taiwan shows various links to those of other Asian regions, yet remarkable differences exist. Notably, R408Q, E286K and -4173&#95;-407del, accounting for 21% of all mutant alleles in Taiwan, are very rare or are undetected among PKU cohorts of other Asian regions to suggest local founder effects. Moreover, the low homozygosity value of 0.092 hints at a high degree of ethnic heterogeneity within the Taiwanese population. Our study of PAH mutation spectrum and the associated haplotypes is useful for subsequent study on the origin and migration pattern via Taiwan, an island at the historical crossroad of migration of ancient populations.

The aim of this study was to: (a) analyze the results of a large-scale newborn screening program for Pompe disease, and (b) establish an effective diagnostic protocol to obtain immediate, valid diagnosis of infantile-onset Pompe disease (IOPD) to promote earlier treatment and better outcomes. In this study, 402,281 newborns were screened for Pompe disease from January 1, 2008 to May 1, 2012. Infants with low acid α-glucosidase (GAA) activity were referred to Taipei Veterans General Hospital for diagnostic confirmation. Physical examination, biochemical parameter (creatine kinase [CK], alanine transaminase, aspartate aminotransferase, and lactate dehydrogenase), and echocardiogram assessments were performed immediately to effectively differentiate IOPD from suspected late-onset Pompe disease (LOPD) or false-positive cases with pseudodeficiency mutation. Six infants with IOPD all presented with hypotonia, extremely low GAA enzyme activity (≤0.5 µmol/L/hr) in initial dried blood spot analysis, high CK (≥250 U/L), and high left ventricular mass index (LVMI, ≥80 g/m(2)). By analyzing these parameters, IOPD was distinguished effectively and immediately from suspected LOPD and false-positive cases. Except for the first referred case, five of the infants with IOPD received first-time enzyme replacement therapy (ERT) within 4 hr of admission and exhibited marked improvement. Our findings indicate that certain clinical manifestations (hypotonia, high CK, enlarged LVMI, and extremely low GAA enzyme activity in initial dried blood spot analysis) can help in the rapid and effective differentiation of patients with IOPD from other patient with low GAA activity. Such differentiation allows for the early application of first-time ERT and leads to better outcomes., (© 2013 Wiley Periodicals, Inc.)

Background: Previous studies revealed a high incidence of late-onset Fabry disease mutation, IVS4+919G>A, in Taiwan. However, the natural course is largely unclear and suitable biomarkers for monitoring disease progress are unavailable., Methods and Results: Patients carrying IVS4+919G>A or classical Fabry mutations were enrolled in this study. The subjects ranged from newborn to eighty year old adults. Plasma globotriaosylceramide (Gb3) and globotriaosylsphingosine (lysoGb3) were measured by LC-MS/MS in subjects to evaluate the sensitivity of these two biomarkers. All adult males and symptomatic females could be distinguished from healthy controls by an elevated plasma lysoGb3 level. The lysoGb3 level was also related to the left ventricular mass considering gender and age (p<0.01). Moreover, approximately 70% of male and 45% of female newborns already had an elevated plasma lysoGb3 level which increased gradually as the subjects got older (p<0.01)., Conclusions: Plasma lysoGb3 is a more sensitive and reliable biomarker than plasma Gb3. LysoGb3 also correlated with age and left ventricular mass index in Fabry patients with IVS4+919G>A mutation. Because lots of infants with the IVS4+919G>A mutation already had elevated lysoGb3 levels at birth, that indicates that the development of hypertrophic cardiomyopathy may require a long and insidious course after lysoGb3 accumulation., (© 2013. Published by Elsevier B.V. All rights reserved.)

Mutations in the phosphate-regulating endopeptidase homolog, X-linked, gene (PHEX), which encodes a zinc-dependent endopeptidase that is involved in bone mineralization and renal phosphate reabsorption, cause the most common form of hypophosphatemic rickets, X-linked hypophosphatemic rickets (XLH). The distribution of PHEX mutations is extensive, but few mutations have been identified in Chinese with XLH. We extracted genomic DNA and total RNA from leukocytes obtained from nine unrelated Chinese subjects (three males and six females, age range 11-36 years) who were living in Taiwan. The PHEX gene was amplified from DNA by PCR, and the amplicons were directly sequenced. Expression studies were performed by reverse-transcription PCR of leukocyte RNA. Serum levels of FGF23 were significantly greater in the patients than in normal subjects (mean 69.4 ± 18.8 vs. 27.2 ± 8.4 pg/mL, P < 0.005), and eight of the nine patients had elevated levels of FGF23. Germline mutations in the PHEX gene were identified in five of 9 patients, including novel c.1843 delA, donor splice site mutations c.663+2delT and c.1899+2T>A, and two previously reported missense mutations, p.C733Y and p.G579R. These data extend the spectrum of mutations in the PHEX gene in Han Chinese and confirm variability for XLH in Taiwan.

Nance-Horan syndrome (NHS) is a rare X-linked disorder characterized by congenital cataracts, dental anomalies and mental retardation. The disease has been linked to a novel gene termed NHS located at Xp22.13. The majority of pathogenic mutations of the disease include nonsense mutations and small deletions and insertions that lead to truncation of the NHS protein. In this study, we identified a microdeletion of ∼ 0.92 Mb at Xp22.13 detected by array-based comparative genomic hybridization in two brothers presenting congenital cataract, dental anomalies, facial dysmorphisms and mental retardation. The deleted region encompasses the REPS2, NHS, SCML1 and RAI2 genes, and was transmitted from their carrier mother who presented only mild cataract. Our findings are in line with several recent case reports to indicate that genomic rearrangement involving the NHS gene is an important genetic etiology underlying NHS.

Information regarding the clinical outcome of enzyme replacement therapy (ERT) with recombinant human N-acetylgalactosamine 4-sulfatase (rhASB) for mucopolysaccharidosis (MPS) VI in Asian patients is limited. We reviewed nine Taiwanese patients with MPS VI (four males and five females; age range 1.4-21.1 years) treated with weekly intravenous infusions of rhASB (1.0 mg/kg) for at least 2 years. We assessed the biochemical and clinical response every 3 months. After 2 years of treatment, seven patients experienced improvement over baseline in the 6-min walk by a mean of 69.3 m (27.3%), and seven also increased the 3-min stair climb by a mean of 47 steps (35.7%). Shoulder range of motion in all patients improved, and Joint Pain and Stiffness Questionnaire scores improved by 0.597 points (30.5%). Four patients had improved pulmonary function [forced expiratory volume in 1 s increased by 0.130 L (26.3%) and forced vital capacity by 0.148 L (27.6%)]. The respiratory disturbance index decreased in the four patients who underwent polysomnography. A mean overall 51% decrease in urinary glycosaminoglycan excretion indicated a satisfactory biochemical response. ERT was well tolerated by all patients. This treatment is thus beneficial and appears to be safe for treatment of MPS VI in Taiwanese patients.

Newborn screening for Fabry disease in Taiwan Chinese has revealed a high incidence of the late-onset GLA mutation IVS4 + 919G→A (∼1 in 1,500-1,600 males). We studied 94 adults with this mutation [22 men, 72 women; mean age: men 57.8 ± 6.0 (range 42-68), women 39.1 ± 14.1 years (range 19-82)]. Plasma α-galactosidase A activity assay was 10.4 ± 11.2% of normal in the men and 48.6 ± 19.5% of normal in the women. Echocardiography in 90 of the adults revealed left ventricular hypertrophy (LVH) in 19 (21%), including 14 of 21 men (67%) and 5 of 69 women (7%). Microalbuminuria, based on the urine albumin-to-creatinine ratio measured on at least two occasions, was present in 17 of 86 subjects (20%) (men: 5/20, 25%; women 12/66, 18%). At least one ocular manifestation consistent with Fabry disease was present in 41 of 52 subjects (79%) who underwent ophthalmologic examination, including 8 (15%) with conjunctival vessel tortuosity, 15 (29%) with cornea verticillata, 10 (19%) with Fabry cataract, and 34 (65%) with retinal vessel tortuosity. Among subjects over 40 years of age, men were more likely than women to have LVH [14/21 (67%) vs 5/25 (20%), p < 0.001]. Cardiovascular, renal and ocular abnormalities are highly prevalent in adult Taiwan Chinese subjects with the Fabry mutation IVS4 + 919G→A. Our findings contribute to the limited understanding of the course of this late-onset disease variant and underscore the need for close follow up in such patients.

In Taiwan, during the period March 2000 to June 2009, 1,495,132 neonates were screened for phenylketonuria (PKU) and homocystinuria (HCU), and 1,321,123 neonates were screened for maple syrup urine disease (MSUD), methylmalonic academia (MMA), medium-chain acyl-coenzyme A (CoA) dehydrogenase (MCAD) deficiency, isovaleric academia (IVA), and glutaric aciduria type 1 (GA-1) using tandem mass spectrometry (MS/MS). In a pilot study, 592,717 neonates were screened for citrullinemia, 3-methylcrotonyl-CoA carboxylase deficiency (3-MCC) and other fatty acid oxidation defects in the MS/MS newborn screening. A total of 170 newborns and four mothers were confirmed to have inborn errors of metabolism. The overall incidence was approximately 1/5,882 (1/6,219 without mothers). The most common inborn errors were defects of phenylalanine metabolism [five classic PKU, 20 mild PKU, 40 mild hyperphenylalaninemia (HPA), and 13 6-pyruvoyl-tetrahydropterin synthase (PTPS) deficiency]. MSUD was the second most common amino acidopathy and, significantly, most MSUD patients (10/13) belonged to the Austronesian aboriginal tribes of southern Taiwan. The most frequently detected among organic acid disorders was 3-MCC deficiency (14 newborns and four mothers). GA-1 and MMA were the second most common organic acid disorders (13 and 13 newborns, respectively). In fatty acid disorders, five carnitine transport defect (CTD), five short-chain acyl-CoA dehydrogenase deficiency (SCAD), and two medium-chain acyl-CoA dehydrogenase (MCAD) deficiency were confirmed. This is the largest case of MS/MS newborn screening in an East-Asian population to date. We hereby report the incidences and outcomes of metabolic inborn error diseases found in our nationwide MS/MS newborn screening program.

Background: Thyroglobulin (TG) defect is a rare cause of congenital hypothyroidism. Although only 44 mutations of the human TG gene have been identified, we have suspected a TG defect in 38% of Taiwan Chinese children/adolescents presenting with moderate or severe thyroidal dyshormonogenesis., Study Objective: The aim of the study is to report the discovery of new TG gene mutations and associated clinical manifestations of the defective TG protein., Patients and Results: In seven patients from six families, we detected six new TG gene mutations, including c.1348delT, p.R432X (c.1351C>T), g.IVS3 + 2T>G, c.1712delT, p.Q1765X (c.5350C>T), and c.6047delA. The c.1348delT and p.R432X mutations were the most common, detected in 33 and 25%, respectively, of alleles studied. Haplotype analysis suggested that the c.1348delT and g.IVS3 + 2T>G mutations are due to founder effects, whereas p.R432X is probably due to independently recurrent de novo mutations. mRNA transcript of the g.IVS3 + 2T>G mutant, detected in whole blood by reverse transcription-nested PCR, showed skipping of exon 3 (98-bp deletion) and a frameshift, with a terminal signal after 17 altered amino acid residues., Conclusions: TG defects have an important role in severe thyroidal dyshormonogenesis (pretreatment, or after a 3-wk T(4) withdrawal, plasma T(4) < or = 30 nmol/liter) in Taiwanese. Its genetic characteristics are markedly different from those described in other populations presenting with mutations of the TG gene.

Previous studies on the incidence of the various types of mucopolysaccharidoses (MPS) in different populations have shown considerable variation. However, information regarding the incidence of MPS in the Asian population is lacking. An epidemiological study of the MPS disorders in Taiwan using multiple ascertainment sources was undertaken, and incidences of different types of MPS during the period of 1984-2004 were estimated. We compared our data with previous reports in different populations. The combined birth incidence for all MPS cases was 2.04 per 100,000 live births. MPS II (Hunter syndrome) had the highest calculated birth incidence of 1.07 per 100,000 live births (2.05 per 100,000 male live births), comprising 52% of all MPS cases diagnosed. The birth incidences of MPS I (Hurler syndrome), III (Sanfilippo syndrome), IV (Morquio syndrome), and VI (Maroteaux-Lamy syndrome) were 0.11, 0.39, 0.33, and 0.14 per 100,000 live births, respectively, which accounted for 6%, 19%, 16%, and 7% of all MPS, respectively. No cases of MPS III D (Sanfilippo syndrome type D), MPS IV B (Morquio syndrome type B), MPS VII (Sly syndrome) or MPS IX were ascertained during the study period. Overall incidence of MPS in Taiwan was consistent with that reported in Western populations. However, in contrast to the higher incidence of MPS I in most Western populations, this study showed a higher incidence of MPS II in Taiwan. It remains to be investigated whether this discrepancy is attributed to the under-diagnosis of MPS I in Taiwan or to ethnic differences.

CYP21A2 mutations resulting from microconversions of the CYP21A1P sequence in congenital adrenal hyperplasia (CAH) commonly appear in all populations. However, it has not often been described as being due to the gene founder effect. Herein, we investigated two spontaneous mutations of IVS2+1G>A and R316X in ethnic Chinese (Taiwanese) CAH patients to determine whether they share the same haplotype of ancient origin by the analysis of sequence-specific oligonucleotide (SSO) for HLA class I B and sequence-based typing (SBT) for HLA class II DRB1 gene-typing methods. From over 200 CAH families, eight unrelated CAH patients were found and examined: five had the IVS2+1G>A mutation and three had the R316X mutation. Based on HLA typing data, five alleles in five patients with the IVS2+1G>A mutation were consistent with a shared haplotype of the B *3909-DRB1 *160201 allele, and the three alleles in the three patients with the R316X mutation were all the B *460101-DRB1 *080302 allele. The evidence indicates that the haplotype of single-base substitutions of either the IVS2+1G>A or R316X mutation came from the same allele rather than a mutational hot spot, suggesting that the gene founder effect has occurred in the Taiwanese population. This is the first report of the gene founder effect of the CYP21A2 mutation occurring in ethnic Chinese (Taiwanese) CAH patients with 21-hydroxylase deficiency.

Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder which causes more than 90% of CAH cases due to defects in the steroid 21-hydroxylase gene (CYP21A2). The frequency of large mutations was determined in 200 ethnic Chinese (i.e., Taiwanese) CAH patients belonging to 200 families with different clinical forms of CYP21A2 deficiency over 10 years of molecular diagnoses. For a large-gene deletion (or conversion) and the CYP21A2 deletion identification, a PCR product covering the TNXB gene and the 5'-end of the CYP21A2 gene with TaqI endonuclease digestion was analyzed by electrophoresis on agarose gels. For CYP21A2 mutational analysis, secondary PCR amplification of the amplification-created restriction site method was applied. From the results of the analysis, we found that large-gene deletions (or conversions) occurred in 7.5% of the alleles including three different types of the chimeric CYP21A1P/CYP21A2 genes and the haplotype of IVS2-12A/C>G in combination with the 707-714del mutation (without the P30L mutation). The CYP21A2 deletion occurred in 2.0% of the alleles which contained three types of the chimeric TNXA/TNXB genes with two novel ones. We concluded that the CYP21A2 deletion in the ethnic Chinese (Taiwanese) patients exhibits a low occurrence, with the haplotype of the IVS2-12A/C>G in combination with the 707-714del mutation (without the P30L mutation) being prevalent among large gene deletions or conversions.

Objective: To report the long-term results of early initiation of treatment of 6-pyruvoyl-tetrahydropterin synthase (PTPS) deficiency., Design: Between 1988 and 2000, 12 newborns with PTPS deficiency who underwent early treatment at our hospital were identified. All patients received tetrahydrobiopterin replacement in a daily dosage between approximately 2 and 4 mg/kg. The dosages of levodopa replacement were 10 to 15 mg/kg/d, which is considerably higher than the typically recommended dosages of less than 7 mg/kg/d for patients aged younger than 2 years and 8 to 10 mg/kg/d for patients aged 2 years or older. Replacement with 5-hydroxytryptophan varied widely among patients., Setting: Taipei Veterans General Hospital. Patients Twelve newborns., Interventions: Treatment with tetrahydrobiopterin, levodopa, and 5-hydroxytryptophan. Main Outcome Measure IQ score., Results: The mean (SD) IQ score of our PTPS-deficient patients was 96.7 (9.7; range 86-119), which is considerably higher than previous reports of other populations of PTPS-deficient patients. All patients reached a normal IQ on high daily dosages of levodopa replacement, without developing apparent long-term levodopa-induced adverse effects. We also observed a correlation between long-term IQ score and genotype, birth weight, and age at initiation of treatment., Conclusions: An effective newborn screening referral program and early initiation of appropriate therapy preserved the IQ scores of PTPS-deficient patients.

Aim: Several different genetic defects have been found to result in the characteristic phenotypic expression of Prader-Willi syndrome (PWS)., Methods: We performed a retrospective analysis of 67 cases of molecularly confirmed PWS diagnosed from January 1980 through July 2006 in five medical centres in Taiwan. Clinical manifestations were compared between patients with deletion and those with maternal uniparental disomy (UPD)., Results: Deletion was present in 56 (84%), UPD in 10 (15%), and a probable imprinting centre deletion or imprinting defect in 1 (1%). PWS with deletion was more likely than that with UPD to be characterized by hypogonadism (p < 0.001), small hands and feet (p < 0.001), and hypopigmentation (p < 0.002). Both maternal (p = 0.015) and paternal age (p = 0.021) were higher in the UPD group. No other clinical features differed significantly different between the two groups., Conclusion: In contrast to most Western populations with a higher incidence of UPD, this study of PWS in Taiwan shows a higher incidence of deletion. There may be subtle phenotypic differences between the UPD and deletion genotypes, but its not clear that these are important clinically.

Background: Prader-Willi syndrome (PWS) is a congenital disorder caused by absent expression of paternal genes in 15q11-13 affecting multiple systems. The information concerning the clinical features of this genetic disorder is incomplete in Taiwan., Methods: A retrospective analysis was carried out of 70 PWS patients (39 male, 31 females; age range, 1 month-22 years) seen in four major medical centers in Taiwan from January 1980 through June 2005. All cases were confirmed by methylation-specific polymerase chain reaction. The molecular characteristics, birth history, clinical presentation and laboratory studies were analyzed., Results: Complete genetic analysis was performed in 52 of the 70 patients with PWS. The abnormalities found included deletions in 45 (87%), maternal uniparental disomy (UPD) in five (10%), and a probable imprinting center deletion or an imprinting defect in two (4%). The average weight of the patients at birth was 2588 +/- 540 g. Bone age delay of >2 years and growth hormone (GH) deficiency were noted in 11/40 (28%) and 12/20 (60%), respectively. In the 18 in whom both bone age and GH were assessed, abnormalities of both were found in two (11%). In 2000, Taiwan instituted the Rare Diseases and Orphan Drugs Act and mandated a three-phase screening protocol for PWS. Of the 41 patients diagnosed with PWS before 2000, only four (10%) were diagnosed before the age of 3 months; in the 29 patients diagnosed after 2000, in 15 (52%) the syndrome was confirmed before 3 months of age (P < 0.001)., Conclusions: The present finding is in contrast to that of most previous reports that indicated a higher incidence of UPD in PWS. It is unclear whether this discrepancy in the incidence of UPD arises from under-diagnosis or because of ethnic differences, a question worthy of further study. The three-phase screening protocol has generated notable improvement in the early diagnosis of PWS in Taiwan.

Marfan syndrome is an autosomal dominant fibrillinopathy caused by mutations of the fibrillin-1 (FBN1) gene. Although linkage analysis is often required to ascertain the disease status in family members, recombination is a problem. We analyzed 6 families including 18 patients using 4 intragenic microsatellite markers, located in intron 1, 5, 28, and 43, respectively, of the FBN1 gene. Haplotypes in all family members could be established, and segregation analysis showed no recombination between the markers and the disease. After confirming the diagnosis, intrafamilial analysis revealed clinical manifestations involving the ocular, cardiac, and skeletal systems. Intragenic linkage analysis in Marfan syndrome is very helpful in its diagnosis and management within affected families.

The mutation of the thyroid peroxidase (TPO) gene that causes the total iodide organification defect (TIOD) is a common and severe condition leading to dyshormonogenesis of the thyroid gland in Caucasians. However, the role of TIOD in Chinese patients with thyroid dyshormonogenesis is unknown. In this study we followed 16 patients from 16 unrelated families in Taiwan and performed perchlorate discharge examination. Seven patients had TIOD and 2 had the partial iodine organification defect (PIOD) among the 16 families. These 9 patients underwent screening in search of TPO gene mutations. Three new mutations (2268 insT, 2243 delT, and G157C) were detected in the 7 patients with TIOD, whereas no mutation in the TPO gene was found in the 2 patients with PIOD. The 2268 insT mutation was noted to be the most common among these TIOD patients (12 of 14 studied alleles, 86%). With 3 intragenic polymorphic markers, we found that the alleles carrying the 2268 insT mutation in Taiwan Chinese TIOD patients were tightly linked to a specific haplotype. The allele frequencies of this haplotype in the 8 patients with homozygous 2268 insT (5 unrelated families, 10 studied alleles) and in 49 normal individuals (98 studied alleles) were 1.00 and 0.02, respectively (P < 0.0001). This indicates that this common novel mutation among Taiwanese patients with TIOD is due to a founder effect.