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Mucolipidosis III alpha/beta (ML III alpha/beta) is an autosomal recessive lysosomal storage disorder caused by N-acetylglucosamine-1-phosphotransferase (GlcNAc-phosphotransferase) deficiency. It is characterized by coarse facial features, developmental delay, short stature, and skeletal deformities. Its cardiovascular symptoms include valvular thickening or hypertrophic cardiomyopathy. A 32-year-old female patient received heart transplantation due to end-stage heart failure caused by dilated cardiomyopathy (DCM). We performed whole exome sequencing to determine the etiology of DCM and/or skeletal deformities. The test revealed c.2715+1G>A and c.3173C>G mutations in the GNPTAB gene encoding the alpha and beta subunits of GlcNAc-phosphotransferase. Finally, she was diagnosed with ML III alpha/beta. This report describes a rare case of ML III alpha/beta associated with DCM. Our findings expand the clinical spectrum of ML III alpha/beta., (© 2018 by the Association of Clinical Scientists, Inc.)

Background: Troponin is considered a primary biomarker for coronary heart disease. We investigated the clinical utility of the Abbott high-sensitivity cardiac troponin I (hs-TnI) assay in patients with various cardiac problems., Methods: Precision was investigated by ten levels of pooled sera and three levels of control materials. We determined Abbott hs-TnI levels in a total of 3314 Korean patients with chest pain, including acute myocardial infarction (n=381), unstable angina (n=327), stable angina (n=1361), variant angina (n=189), non-coronary artery diseases (n=236), and nonspecific chest pain (n=820). The 99(th) percentile cutoff was established by the plasma from the cardio-healthy subgroup and validated by 118 healthy individuals., Results: The total coefficient of variation in patient pooled sera and controls ranged from 3.93-6.35% and 4.81-9.73%, respectively. There was a significant difference in hs-TnI among various cardiac problems: subjects with non-cardiac chest pain (median 1.7 pg/mL, 25%/75% quartile 1.1/2.8 pg/mL), variant angina (2.4 pg/mL,1.4/5.6 pg/mL), stable angina (3.7 pg/mL, 2.1/8.9 pg/mL), unstable angina (10.7 pg/mL, 3.7/61.7 pg/mL), and non-coronary artery diseases (9.3 pg/mL, 4.3/37.4 pg/mL). However, the median levels of hs-TnI were not statistically different (p=0.921) between unstable angina and non-coronary artery diseases. The overall 99(th) percentile cutoff was 19.3 pg/mL (range 0.2-30.6 pg/mL)., Conclusions: This new hs-TnI assay may be helpful in determining a differential diagnosis in patients with chest pain., (© 2015 by the Association of Clinical Scientists, Inc.)

Background: Hereditary tyrosinemia type I (HT I) is a severe inborn metabolic disorder affecting the tyrosine degradation pathway. Most untreated patients die within the first two years of life. HT I results from fumarylacetoacetate hydrolase (FAH) deficiency caused by mutations in the FAH gene. The diagnosis of HT I is confirmed by measuring FAH enzyme activity in cultured fibroblasts or liver tissue and/or detecting disease-causing mutations in the FAH gene., Methods: A female neonate was referred to our hospital for further evaluation of an abnormal newborn screening test that showed elevated tyrosine levels. We analyzed amino acids and organic acids in the patient's blood and urine. To identify the genetic abnormality, all the coding exons and flanking introns of the FAH gene were analyzed via PCR., Results: A repeat newborn screening test and plasma amino acid analysis revealed increased tyrosine levels in the patient. Urine organic acid analysis showed increased urinary excretion of 4-hydroxyphenyllactate, 4-hydroxyphenylpyruvate, and succinylacetone. Sequence analysis of the FAH gene identified two novel variations (c.536A>G (p.Gln179Arg) and c.913+5G>A) that had not been previously reported and that were not found in 170 healthy controls., Conclusions: HT I was confirmed in this patient by molecular genetic analysis of the FAH gene, with highly suggestive biochemical findings. The novel sequence variations detected in the present study should be considered disease-causing mutations by in silico analysis. In the Korean population, this is the first described case of HT I caused by a point mutation in the FAH gene., (© 2014 by the Association of Clinical Scientists, Inc.)

Mutations in the glutaryl-CoA dehydrogenase gene can result in Glutaric aciduria type 1(GA 1) by accumulation of glutaric acid, 3-hydroxyglutaric acid (3-OH-GA), and glutarylcarnitine (C5DC). GA 1 is characterized by macrocephaly, subdural hemorrhage (SDH), and dystonic movement disorder after acute encephalopathic crisis. We report a Korean patient with GA1 and a novel mutation. A 16-month-old boy presented with SDH, macrocephaly, and developmental delay. In the neurologic examination, the patient had mild axial hypotonia, but otherwise normal neurologic functions. The brain MRI showed large amounts of bilateral SDH and high signal intensity in both basal ganglia and thalamus. Metabolic screening tests detected highly elevated urinary GA levels but 3-OH-glutaric acid was normal. C5DC was 0.94 μM/L (reference range < 0.3 μM/L). The patient had compound heterozygous mutations of the GCDH gene: p.Arg257Gln (c.770G>A) and p.Cys308Arg (c.922T>C). p.Cys308Arg is a novel mutation; reports of p.Arg257Gln were also rare both in Caucasians and Asian populations. In summary, we hereby report one Korean patient with GA1 with clinical, biochemical, and radiologic characteristics confirmed by genetic analysis.

Background: Hyperprolinemia is a rare inherited metabolic disorder characterized by a high proline level in blood and/or urine and various neuropsychiatric symptoms. Type I hyperprolinemia is caused by a proline oxidase deficiency, which is encoded by the PRODH gene on chromosome 22q11. Herein, we present a study of Korean patients with type I hyperprolinemia who were diagnosed during newborn screening by tandem mass spectrometry and confirmed by molecular analysis., Methods: Four neonates were referred to our hospital for workup of high proline levels in newborn screening test. We analyzed the biochemical findings and the PRODH gene was amplified by long-range PCR to confirm molecular genetic abnormalities., Results: All patients had high plasma proline levels, ranging from 742 to 1192 μmol/L (reference range, 77.4 - 244.6 μmol/L). In molecular analysis, 4 disease-associated mutant alleles were identified: c.1414G>A (p.A472T), c.1279G>A (p.V427M), c.1357C>T (p.R453C) and c.1562A>G (p.Q521R). All mutations were missense and c.1279G>A included the majority of mutant alleles. No relationships between type of mutation and clinical outcomes were observed., Conclusion: We found that distinct molecular alterations of the PRODH gene result in abnormal proline levels. Newborn screening and molecular analysis are necessary to identify patients before clinical expression of metabolic disease.

Background: Glycogen storage disease II (GSD II) is caused by a deficiency of acid alpha-1,4-glucosidase and mutations in the GAA gene encoding this enzyme which are responsible for the pathogenesis of GSD II. Our goal was to determine the mutational spectrum in the GAA gene in Korean patients with GSD II., Methods: Three patients with GSD II were recruited based on clinical and biochemical findings. Alpha-1,4-glucosidase activity was determined and the GAA gene sequence was analyzed by PCR and sequencing. We also collected information about the genotypes of Korean patients with GSD II from the medical literature., Results: We identified six mutant alleles among the three GSD II patients: c.875A>G, c.1156C>T, c.1316T>A, c.1857C>G, and c2407&#95;2412del7. c.1156C>T (Q386*) is a novel mutation. A comprehensive review of the literature revealed that a total of 29 mutant alleles, including 15 different mutations (10 missense, 3 deletion, and 2 nonsense mutations), were previously identified in 15 Korean GSD II patients. c.1316T>A (p.M439K) and c.1857C>G (p.S619R) were the most common mutations and accounted for 36.6% of the total mutant alleles., Conclusions: We identified three GSD II patients and investigated the mutational spectrum in GAA in Korean patients with GSD II. Our results indicate that common mutations in the GAA gene vary according to ethnic background.

Mutations in the GLB1 gene, which encodes acid β-galactosidase, can result in two disease phenotypes: GM1-gangliosidosis (MIM #230500) and Morquio B disease (Mucopolysaccharidosis type IVB, MIM #253010). Morquio B disease occurs much more infrequently than GM1-gangliodosis and is characterized by severe skeletal manifestations (dysostosis multiplex) without central nervous system involvement. Here, we report the first known Korean patient with Morquio B disease. A 7-year-old boy presented with severe progressive skeletal dysplasia including scoliosis, contractures of the elbows, xenu valgum, funnel chest, and trigger thumb requiring surgical intervention. The patient had normal neurological functions and mental status when evaluated by pediatric neurologists. The patient's urinary glycosaminoglycans, measured by the cetylpyridinium chloride (CPC) precipitation test, were 252.8 CPC unit/g creatinine (reference range < 175). Thin layer chromatography of urine showed a keratan sulfate band. Enzyme activity of β-galactosidase in leukocytes was 1.15 nmol/hr/mg protein (reference range 78.1-117.7; 1-1.5% of normal). The patient had compound heterozygous mutations of the GLB1 gene: c.13&#95;14insA (p.L5HfsX29), which was reported in a patient with infantile GM1 gangliosidosis with the near-complete absence of enzyme activity, and c.367G>A (p.G123R), which is a novel frame-shift mutation. In summary, we report the first known Korean patient with Morquio B disease and a novel mutation (c.13&#95;14insA of GLB1).

Background Vancomycin is used for the treatment of resistant staphylococcal and enterococcal infections but is associated with nephrotoxicity. Neutrophil gelatinase-associated lipocalin (NGAL) was recently identified as a sensitive biomarker for acute kidney injury. Here, we aimed to investigate the usefulness of serum NGAL in monitoring patients undergoing vancomycin therapy. Methods A total of 253 NGAL tests from 59 patients undergoing vancomycin therapy were evaluated. Patients with trough serum concentrations of vancomycin that exceeded 20 ug/mL were included. Serum NGAL was measured using a commercially available ELISA kit, and other biochemical indicators including creatinine, leukocyte count, eGFR and C-reactive protein were assessed. Results At the initiation of vancomycin treatment, serum creatinine level was 0.93 ± 0.40 (mean ± SD) mg/dL, NGAL was 341 ± 354 mg/dL, leukocyte count was 10,750 ± 7190 per uL and CRP level was high (10.8 ± 9.3 mg/dL). About 49% of patients had an elevated leukocyte count, and all patients showed a high CRP level. Basal serum NGAL concentration in the patients with elevated leukocyte level (10,000/uL or higher) was higher compared to that in patients with normal leukocyte levels (mean ± SD, 478 ± 449 mg/dL vs. 176 ± 101 mg/dL, p<0.001). A significant positive relationship was found between NGAL level and creatinine level in patients with normal basal leukocyte levels but not in those with higher leukocytes. Conclusion The clinical usefulness of serum NGAL should be interpreted carefully when evaluating renal impairment in patients undergoing vancomycin treatment.

Systemic primary carnitine deficiency (CDSP) is a rare autosomal recessive disorder that presents episodic periods of hypoketotic hypoglycemia. The main symptoms of CDSP are skeletal and cardiac myopathy. CDSP is caused by a defect in plasma membrane uptake of carnitine, ultimately caused by the SLC22A5 gene. We report the case of a Korean patient with CDSP. He had an abnormal free carnitine level of 5.56 μmol/L (reference range, RR 10.4~87.1 μmol/L) and a palmitoylcarnitine level of 0.27 μmol/L (RR 0.5~9.7 μmol/L) in a newborn screening test. The patient showed an ammonia level of 129.4 ug/dL (RR, 25~65 ug/dL), a lactate level of 4.5 mmol/L (RR, 0.5-2.2 mmol/L), and a free carnitine level of 10.3 μmol/L (RR, 36-74 μmol/L) in blood. After PCR-sequencing analysis of the SLC22A5 gene, the patient was found to be a compound heterozygote for c.506G>A (p.R169Q) and c.1400C>G (p.S467C) mutations. These missense mutations are reported previously. The patient was started on L-carnitine supplement after CDSP diagnosis. The patient was treated with L-carnitine to reach a normal free carnitine level and has remained asymptomatic up to the current age of 21 months. The plasma free carnitine level normalized to 66.6 μmol/L at 4 weeks after treatment. To the best of our knowledge, this is the first report of a CDSP patient confirmed by molecular genetic investigation.

Tricho-rhino-phalangeal syndrome type I (TRPSI) is a rare autosomal dominant hereditary disorder characterized by sparse hair, bulbous nose, long philtrum, thin upper lip, and skeletal abnormalities including cone-shaped epiphyses, shortening of the phalanges, and short stature. TRPSI is caused by mutations in the TRPS1 gene. Herein, we report two Korean cases of TRPSI. Although both patients (a 17-year-old-female and a 14-year-old male) had typical clinical findings, Patient 1 had an additional growth hormone (GH) deficiency. Treatment with recombinant human growth hormone (rhGH) 0.7 IU/kg/week led to an increase in growth velocity. Over 10 years of GH therapy, the mean growth velocity was 5.7 ± 0.9 cm/year. However, the patient 2 did not show apparent GH deficiency by GH stimulation test, had a poor response with rhGH therapy and GH therapy was discontinued after 6 months. Upon genetic analysis of the TRPS1 gene, two mutations were found. Patient 1 had a heterozygous mutation c.2520dupT (p.Arg841LysfsX3) which had not been previously reported. Patient 2 had a known nonsense mutation c.1630C>T (p.Arg544X). In summary, we were the first to report Korean patients with mutation of TRPS1.

Mutations in the CYP21A2 gene encoding the 21-hydroxylase enzyme account for >90% of congenital adrenal hyperplasia (CAH) cases. Approximately 20% of mutant alleles carrying large deletion/duplication have also been reported. Herein, we describe the use of the multiplex ligation-dependent probe amplification (MLPA) method for convenient and rapid detection of deletions/duplications in the CYP21A2 gene. We used MLPA to analyze the gene dose of CYP21A2 MLPA in 13 Korean patients who previously underwent direct sequencing for the molecular diagnosis of CAH. The MLPA assays identified 5 patients with CYP21A2 deletions; all 5 patients carried a single mutant allele peak in sequence analysis. These results demonstrate the diagnostic usefulness of MLPA to detect CYP21A2 deletions/duplications for diagnosis of CAH.

Short-chain acyl-coenzyme A dehydrogenase deficiency (SCADD) is an autosomal recessive disorder of mitochondrial fatty acid oxidation associated with mutations in the ACADS gene (Acyl-CoA Dehydrogenase, Short-chain, OMIM #606885). SCADD is a heterogeneous condition that has been associated with various clinical phenotypes ranging from fetal metabolic decompensation in infancy to asymptomatic individuals. Here, the first Korean neonate diagnosed with SCADD by biochemical and genetic findings is reported. The patient has remained asymptomatic by avoiding hypoglycemia. An increased concentration of butylcarnitine was detected on newborn screening. Subsequent urine organic acid analysis showed increased urinary excretion of ethylmalonic acid. To confirm the presence of the genetic abnormality, all the coding exons of the ACADS gene and flanking introns were amplified by the polymerase chain reaction (PCR). Sequence analysis of the ACADS gene revealed novel homozygous missence mutations, c. 1031A>G (p.E344G) in exon 9. In summary, the first Korean patient with confirmed SCADD by genetic analysis is reported with novel mutation.

X-linked liver glycogenosis (XLG) is caused by a mutation in the PHKA2 gene which encodes the alpha subunit of phosphorylase kinase (PHK). Although XLG is not a rare disease, there have been no reports of PHKA2 mutations in Koreans. A 5-year-old boy presented with easy fatigability and hepatomegaly. Liver enzymes were increased and liver histology revealed deposition of glycogen. The PHK activity was markedly decreased compared to control. No amplification was observed at exon 8 of the PHKA2 gene, as a result of the deletion of exon 8. Sequence analysis revealed a hemizygous deletion in the region of exon 8 (c.717+781&#95;864+225del1626). The patient was diagnosed as having XLG I. To the best of our knowledge, this is the first report of XLG I in Koreans.

Maple syrup urine disease (MSUD) is a rare, autosomal recessive disorder of branched-chain amino acid (BCAA) metabolism caused by dysfunction of the multienzyme branched-chain alpha-ketoacid dehydrogenase (BCKDH) complex. Although a few cases of MSUD have been reported in the Korean population, the genetic background of MSUD is not well understood. In this study, we investigated three newborn males who were diagnosed with MSUD using a standard newborn screening test and amino acid analysis. We screened all coding regions of the BCKDHA, BCKDHB and DBT genes for abnormalities using direct sequencing. Changes in these genes are associated with MSUD. For one patient with complex deletion/duplication mutations, we also performed TOPO TA cloning sequencing. Amino acid analysis showed elevated levels of all branched chain amino acids (BCAAs) in all patients. Three patients were either homozygous or compound heterozygous for the BCKDHA mutations. Patient 1 was homozygous for c.1036C>T (p.R346C); patient 2 was heterozygous, with c.632C>T (p.T211M) and c.659C>T (p.A220V); and patient 3 had c.1204&#95;1209dupAAACCC (p.L402&#95;P403dup) and c.1280&#95;1282delTGG (p.L427&#95;A428delinsP). Among these mutations, c.1036C>T, c.632C>T, c.1204&#95;1209dup and c.1280&#95;1282del were novel. These patients had no mutations in either the BCKDHB or the DBT gene. Although this study included only three patients, the five different mutations in these patients may indicate mutational heterogeneity in Korean patients with MSUD. In addition, the BCHDHA gene may present a primary target for clinical genetic analysis. To the best of our knowledge, this is the first report of genetically confirmed MSUD in Korea.

Peroxisome biogenesis disorders (PBD) represent a spectrum of genetic disorders characterized by impaired peroxisome assembly. Zellweger syndrome (ZS) is the most severe form of PBD and is characterized by craniofacial abnormalities, severe hypotonia, neonatal seizures, ocular abnormalities, psychomotor retardation, hepatomegaly and increased levels of very long chain fatty acids (VLCFA). The most common mutation associated with the PBD is PEX1. Here, the first Korean patient with ZS confirmed by clinical, biochemical, and molecular findings is reported. Two novel mutations of the PEX1 gene were identified in the patient with ZS. The patient was a compound heterozygote for c.2034&#95;2035delCA and c.2845C>T mutations of the PEX1 gene. Both mutations are novel findings and were inherited from the patient's parents. In summary, here the first Korean case of ZS is reported that was confirmed by two novel mutations of the PEX1 gene.

Wilson disease (WD) is an autosomal recessive disorder caused by mutations in the ATP7B gene, yet many patients have either one mutation, or no mutation. We investigated whether the mutation detection rate is associated with any biochemical characteristics of WD. In a study of 71 patients, we used PCR-sequencing to screen for ATP7B mutations in 7 exons (exons 8, 10, 11, 14, 15, 16, and 18) covering 95% of known mutations in Korean patients with WD. We also investigated serum concentrations of various biochemical analytes. Data were analyzed by linear association test and one-way ANOVA. Based on the number of detected ATP7B mutations, a significant difference in serum ceruloplasmin concentration was found among the 3 groups (p <0.001). Serum ceruloplasmin concentration averaged 3.32 +/- 1.74, 10.8 +/- 5.50, and 14.9 +/- 3.88 mg/dl (mean +/- SD) in the 25, 20, and 26 patients with two, one, and no ATP7B mutations, respectively. We observed 82.9% and 16.7% of mutant allele frequency in WD patients with ceruloplasmin concentration <10 mg/dl and 10-20 mg/dl, respectively (p <0.001). Thus serum ceruloplasmin concentrations among WD patients differed according to the number of ATP7B mutations detected.

Cornelia de Lange syndrome (CdLS; OMIM #122470) is a multiple congenital anomaly with characteristic facial features, growth delay, mental retardation, limb defects, behavioral problems, ocular and hearing impairments, and gastrointestinal or cardiac abnormalities. Although the NIPBL gene has been identified as a causative gene for CdLS, there has hitherto been no genetically confirmed case of CdLS in Korea. Herein, we report a clinical and genetic analysis of three Korean patients with clinical features consistent with CdLS. A male neonate had distinctive facial features, malformations of the upper extremities, genital abnormalities, and bilateral hearing loss, while a 6-yr-old boy and a 10-yr-old girl had distinctive facial features, short stature, and mental retardation. There were no chromosomal abnormalities in the three children. Sequence analysis of the NIPBL gene revealed three novel NIPBL variations including c.6108+2T>C, c.4028A>C (p.His1343Pro), and c.218C>T (p.Ser73Leu) in each patient, respectively. The first two variations appear to be de novo mutations causing CdLS in the patients because they are absent in the patients' parents. The p.Ser73Leu variation, however, seems to be a polymorphism since it is found both in the patient and in her asymptomatic mother. To the best of our knowledge, this is the first report of genetically confirmed cases of CdLS in Korea and extends the mutation spectrum of the NIPBL gene.

Pseudohypoparathyroidism (PHP) comprises a heterogeneous group of endocrine disorders with the common feature of resistance to parathormone (PTH), manifested by hypocalcemia, hyperphosphatemia, and elevation of serum PTH despite normal renal function. Herein, the first Korean cases of PHP type Ia are reported. The two patients (6-yr-old female, 7-yr-old male) had typical signs of Albright hereditary osteodystrophy. Genomic DNA was isolated from their peripheral blood leukocytes and the GNAS gene was amplified by PCR and analysed by bidirectional sequencing including all coding exons. Two GNAS mutations were found: c.94A>T and c.344&#95;345insT. Patient 1 had a nonsense mutation of c.94A>T (p. K32X), which has not been previously described; the mother also had c.94A>T, and it therefore was a familial mutation. Patient 2 had a known frame shift mutation for c.344&#95;345insT (p.V117RfsX23). The family members of patient 2 had wild-type sequences. In summary, two Korean patients with PHP-Ia were confirmed by genetic analysis and a novel p.K32X product of the GNAS mutation was identified.

Mitochondrial trifunctional protein (MTP) is a heterocomplex composed of 4 alpha-subunits containing LCEH (long-chain 2,3-enoyl-CoA hydratase) and LCHAD (long-chain 3-hydroxyacyl CoA dehydrogenase) activity, and 4 beta-subunits that harbor LCKT (long-chain 3-ketoacyl-CoA thiolase) activity. MTP deficiency is an autosomal recessive disorder that causes a clinical spectrum of diseases ranging from severe infantile cardiomyopathy to mild chronic progressive polyneuropathy. Here, we report the case of a Korean male newborn who presented with severe lactic acidosis, seizures, and heart failure. A newborn screening test and plasma acylcarnitine profile analysis by tandem mass spectrometry showed an increase of 3-hydroxy species: 3-OH-palmitoylcarnitine, 0.44 nmol/ml (reference range, RR <0.07); 3-OH-linoleylcarnitine, 0.31 nmol/ml (RR <0.06); and 3-OH-oleylcarnitine, 0.51 nmol/ml (RR <0.04). These findings suggested either long-chain 3-hydroxyacyl-coA dehydrogenase deficiency or complete MTP deficiency. By molecular analysis of the HADHB gene, the patient was found to be a compound heterozygote for c.358dupT (p.A120CfsX8) and c.1364T>G (p.V455G) mutations. These 2 mutations of the HADHB gene were novel and inherited. Although the patient was treated by reduction of glucose administration and supplementation of a medium-chain triglyceride-based diet with L-carnitine, he died 2 mo after birth due to advanced cardiac failure.

Menkes disease (MD, MIM 309400) is a fatal X-linked recessive disorder that is caused by mutations in the gene encoding ATP7A, a copper-transporting, P-type ATPase. Patients with MD are characterized by progressive hypotonia, seizures, failure to thrive, and death in early childhood. Two Korean patients were diagnosed with Menkes disease by clinical and biochemical findings. We found one missense mutation and one gross deletion in the ATP7A gene in the patients. The missense mutation in Patient 1, c.3943G>A (p.G1315R) in exon 20, was identified in a previous report. Patient 2 had a gross deletion of c.1544-?&#95;2916+?, which was a novel mutation. The patients' mothers were shown to be carriers of the respective mutations. Prenatal DNA diagnosis in the family of Patient 2 was successfully performed, showing a male fetus with the wild-type genotype. The gross deletion is the first mutation to be identified in the ATP7A gene in Korean MD patients. We expect that our findings will be helpful in understanding the wide range of genetic variation in ATP7A in Korean MD patients.