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Item does not contain fulltext, With the rapid advancement of medical technologies in genomic and molecular medicine, the number of treatable neurometabolic diseases is quickly expanding. Spastic paraplegia 56 (SPG56), one of the severe autosomal recessive forms of neurodegenerative disorders caused by pathogenic variants in the CYP2U1 gene, has no reported specific targeted treatment yet. Here we report 2 Chinese brothers with CYP2U1 bi-allelic pathogenic variants with cerebral folate deficiency who were treated for over a decade with folinic acid supplement. Patients have remained stable under therapy.

Item does not contain fulltext, Immunological problems are increasingly acknowledged manifestations in many inherited metabolic diseases (IMDs), ranging from exaggerated inflammation, autoimmunity and abnormal cell counts to recurrent microbial infections. A subgroup of IMDs, the congenital disorders of glycosylation (CDG), includes CDG types that are even classified as primary immunodeficiencies. Here, we reviewed the list of metabolic disorders reported to be associated with various immunological defects and identified 171 IMDs accompanied by immunological manifestations. Most IMDs are accompanied by immune dysfunctions of which immunodeficiency and infections, innate immune defects, and autoimmunity are the most common abnormalities reported in 144/171 (84%), 44/171 (26%) and 33/171 (19%) of IMDs with immune system involvement, respectively, followed by autoinflammation 17/171 (10%). This article belongs to a series aiming at creating and maintaining a comprehensive list of clinical and metabolic differential diagnoses according to organ system involvement.

Item does not contain fulltext, Ocular manifestations are observed in approximately one third of all inherited metabolic disorders (IMDs). Although ocular involvement is not life-threatening, it can result in severe vision loss, thereby leading to an additional burden for the patient. Retinal degeneration with or without optic atrophy is the most frequent phenotype, followed by oculomotor problems, involvement of the cornea and lens, and refractive errors. These phenotypes can provide valuable clues that contribute to its diagnosis. In this issue we found 577 relevant IMDs leading to ophthalmologic manifestations. This article is the seventh of a series attempting to create and maintain a comprehensive list of clinical and metabolic differential diagnoses according to system involvement.

Contains fulltext : 248205.pdf (Publisher’s version ) (Open Access), Ocular manifestations are observed in approximately one third of all inherited metabolic disorders (IMDs). Although ocular involvement is not life-threatening, it can result in severe vision loss, thereby leading to an additional burden for the patient. Retinal degeneration with or without optic atrophy is the most frequent phenotype, followed by oculomotor problems, involvement of the cornea and lens, and refractive errors. These phenotypes can provide valuable clues that contribute to its diagnosis. In this issue we found 577 relevant IMDs leading to ophthalmologic manifestations. This article is the seventh of a series attempting to create and maintain a comprehensive list of clinical and metabolic differential diagnoses according to system involvement.

Contains fulltext : 248205.pdf (Publisher’s version ) (Open Access), Ocular manifestations are observed in approximately one third of all inherited metabolic disorders (IMDs). Although ocular involvement is not life-threatening, it can result in severe vision loss, thereby leading to an additional burden for the patient. Retinal degeneration with or without optic atrophy is the most frequent phenotype, followed by oculomotor problems, involvement of the cornea and lens, and refractive errors. These phenotypes can provide valuable clues that contribute to its diagnosis. In this issue we found 577 relevant IMDs leading to ophthalmologic manifestations. This article is the seventh of a series attempting to create and maintain a comprehensive list of clinical and metabolic differential diagnoses according to system involvement.

Contains fulltext : 220018.pdf (Publisher’s version ) (Closed access), OBJECTIVE: This study aimed to investigate and improve the usefulness of the 48-hour BH(4) loading test and to assess genotype for BH(4) responsiveness prediction, using the new definition of BH(4) responsiveness from the European guidelines, as well as an amended definition. METHOD: Applying the definition of the European guidelines (≥100% increase in natural protein tolerance) and an amended definition (≥100% increase in natural protein tolerance or tolerating a safe natural protein intake) to a previous dataset, we first assessed the positive predictive value (PPV) of the 48-hour BH(4) loading test using a cutoff value of 30%. Then, we tried to improve this PPV by using different cutoff values and separate time points. Last, using the BIOPKU database, we compared predicted BH(4) responsiveness (according to genotype) and genotypic phenotype values (GPVs) in BH(4) -responsive and BH(4) -unresponsive patients. RESULTS: The PPV of the 48-hour loading test was 50.0% using the definition of the European guidelines, and 69.4% when applying the amended definition of BH(4) responsiveness. Higher cutoff values led to a higher PPV, but resulted in an increase in false-negative tests. Parameters for genotype overlapped between BH(4) -responsive and BH(4) -unresponsive patients, although BH(4) responsiveness was not observed in patients with a GPV below 2.4. CONCLUSION: The 48-hour BH(4) loading test is not as useful as previously considered and cannot be improved easily, whereas genotype seems mainly helpful in excluding BH(4) responsiveness. Overall, the definition of BH(4) responsiveness and BH(4) responsiveness testing require further attention.

Contains fulltext : 220018.pdf (Publisher’s version ) (Closed access), OBJECTIVE: This study aimed to investigate and improve the usefulness of the 48-hour BH(4) loading test and to assess genotype for BH(4) responsiveness prediction, using the new definition of BH(4) responsiveness from the European guidelines, as well as an amended definition. METHOD: Applying the definition of the European guidelines (≥100% increase in natural protein tolerance) and an amended definition (≥100% increase in natural protein tolerance or tolerating a safe natural protein intake) to a previous dataset, we first assessed the positive predictive value (PPV) of the 48-hour BH(4) loading test using a cutoff value of 30%. Then, we tried to improve this PPV by using different cutoff values and separate time points. Last, using the BIOPKU database, we compared predicted BH(4) responsiveness (according to genotype) and genotypic phenotype values (GPVs) in BH(4) -responsive and BH(4) -unresponsive patients. RESULTS: The PPV of the 48-hour loading test was 50.0% using the definition of the European guidelines, and 69.4% when applying the amended definition of BH(4) responsiveness. Higher cutoff values led to a higher PPV, but resulted in an increase in false-negative tests. Parameters for genotype overlapped between BH(4) -responsive and BH(4) -unresponsive patients, although BH(4) responsiveness was not observed in patients with a GPV below 2.4. CONCLUSION: The 48-hour BH(4) loading test is not as useful as previously considered and cannot be improved easily, whereas genotype seems mainly helpful in excluding BH(4) responsiveness. Overall, the definition of BH(4) responsiveness and BH(4) responsiveness testing require further attention.

Contains fulltext : 220018.pdf (Publisher’s version ) (Closed access), OBJECTIVE: This study aimed to investigate and improve the usefulness of the 48-hour BH(4) loading test and to assess genotype for BH(4) responsiveness prediction, using the new definition of BH(4) responsiveness from the European guidelines, as well as an amended definition. METHOD: Applying the definition of the European guidelines (≥100% increase in natural protein tolerance) and an amended definition (≥100% increase in natural protein tolerance or tolerating a safe natural protein intake) to a previous dataset, we first assessed the positive predictive value (PPV) of the 48-hour BH(4) loading test using a cutoff value of 30%. Then, we tried to improve this PPV by using different cutoff values and separate time points. Last, using the BIOPKU database, we compared predicted BH(4) responsiveness (according to genotype) and genotypic phenotype values (GPVs) in BH(4) -responsive and BH(4) -unresponsive patients. RESULTS: The PPV of the 48-hour loading test was 50.0% using the definition of the European guidelines, and 69.4% when applying the amended definition of BH(4) responsiveness. Higher cutoff values led to a higher PPV, but resulted in an increase in false-negative tests. Parameters for genotype overlapped between BH(4) -responsive and BH(4) -unresponsive patients, although BH(4) responsiveness was not observed in patients with a GPV below 2.4. CONCLUSION: The 48-hour BH(4) loading test is not as useful as previously considered and cannot be improved easily, whereas genotype seems mainly helpful in excluding BH(4) responsiveness. Overall, the definition of BH(4) responsiveness and BH(4) responsiveness testing require further attention.

Contains fulltext : 220018.pdf (Publisher’s version ) (Closed access), OBJECTIVE: This study aimed to investigate and improve the usefulness of the 48-hour BH(4) loading test and to assess genotype for BH(4) responsiveness prediction, using the new definition of BH(4) responsiveness from the European guidelines, as well as an amended definition. METHOD: Applying the definition of the European guidelines (≥100% increase in natural protein tolerance) and an amended definition (≥100% increase in natural protein tolerance or tolerating a safe natural protein intake) to a previous dataset, we first assessed the positive predictive value (PPV) of the 48-hour BH(4) loading test using a cutoff value of 30%. Then, we tried to improve this PPV by using different cutoff values and separate time points. Last, using the BIOPKU database, we compared predicted BH(4) responsiveness (according to genotype) and genotypic phenotype values (GPVs) in BH(4) -responsive and BH(4) -unresponsive patients. RESULTS: The PPV of the 48-hour loading test was 50.0% using the definition of the European guidelines, and 69.4% when applying the amended definition of BH(4) responsiveness. Higher cutoff values led to a higher PPV, but resulted in an increase in false-negative tests. Parameters for genotype overlapped between BH(4) -responsive and BH(4) -unresponsive patients, although BH(4) responsiveness was not observed in patients with a GPV below 2.4. CONCLUSION: The 48-hour BH(4) loading test is not as useful as previously considered and cannot be improved easily, whereas genotype seems mainly helpful in excluding BH(4) responsiveness. Overall, the definition of BH(4) responsiveness and BH(4) responsiveness testing require further attention.

Contains fulltext : 195728.pdf (publisher's version ) (Open Access), BACKGROUND: Phenylketonuria (PKU) is often considered as the classical example of a genetic disorder in which severe symptoms can nowadays successfully be prevented by early diagnosis and treatment. In contrast, untreated or late-treated PKU is known to result in severe intellectual disability, seizures, and behavioral disturbances. Rarely, however, untreated or late-diagnosed PKU patients with high plasma phenylalanine concentrations have been reported to escape from intellectual disability. The present study aimed to review published cases of such PKU patients. METHODS: To this purpose, we conducted a literature search in PubMed and EMBASE up to 8th of September 2017 to identify cases with 1) PKU diagnosis and start of treatment after 7 years of age; 2) untreated plasma phenylalanine concentrations >/=1200 mumol/l; and 3) IQ >/=80. Literature search, checking reference lists, selection of articles, and extraction of data were performed by two independent researchers. RESULTS: In total, we identified 59 published cases of patients with late-diagnosed PKU and unexpected favorable outcome who met the inclusion criteria. Although all investigated patients had intellectual functioning within the normal range, at least 19 showed other neurological, psychological, and/or behavioral symptoms. CONCLUSIONS: Based on the present findings, the classical symptomatology of untreated or late-treated PKU may need to be rewritten, not only in the sense that intellectual dysfunction is not obligatory, but also in the sense that intellectual functioning does not (re)present the full picture of brain damage due to high plasma phenylalanine concentrations. Further identification of such patients and additional analyses are necessary to better understand these differences between PKU patients.

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Contains fulltext : 195728.pdf (publisher's version ) (Open Access), BACKGROUND: Phenylketonuria (PKU) is often considered as the classical example of a genetic disorder in which severe symptoms can nowadays successfully be prevented by early diagnosis and treatment. In contrast, untreated or late-treated PKU is known to result in severe intellectual disability, seizures, and behavioral disturbances. Rarely, however, untreated or late-diagnosed PKU patients with high plasma phenylalanine concentrations have been reported to escape from intellectual disability. The present study aimed to review published cases of such PKU patients. METHODS: To this purpose, we conducted a literature search in PubMed and EMBASE up to 8th of September 2017 to identify cases with 1) PKU diagnosis and start of treatment after 7 years of age; 2) untreated plasma phenylalanine concentrations >/=1200 mumol/l; and 3) IQ >/=80. Literature search, checking reference lists, selection of articles, and extraction of data were performed by two independent researchers. RESULTS: In total, we identified 59 published cases of patients with late-diagnosed PKU and unexpected favorable outcome who met the inclusion criteria. Although all investigated patients had intellectual functioning within the normal range, at least 19 showed other neurological, psychological, and/or behavioral symptoms. CONCLUSIONS: Based on the present findings, the classical symptomatology of untreated or late-treated PKU may need to be rewritten, not only in the sense that intellectual dysfunction is not obligatory, but also in the sense that intellectual functioning does not (re)present the full picture of brain damage due to high plasma phenylalanine concentrations. Further identification of such patients and additional analyses are necessary to better understand these differences between PKU patients.

Contains fulltext : 195728.pdf (publisher's version ) (Open Access), BACKGROUND: Phenylketonuria (PKU) is often considered as the classical example of a genetic disorder in which severe symptoms can nowadays successfully be prevented by early diagnosis and treatment. In contrast, untreated or late-treated PKU is known to result in severe intellectual disability, seizures, and behavioral disturbances. Rarely, however, untreated or late-diagnosed PKU patients with high plasma phenylalanine concentrations have been reported to escape from intellectual disability. The present study aimed to review published cases of such PKU patients. METHODS: To this purpose, we conducted a literature search in PubMed and EMBASE up to 8th of September 2017 to identify cases with 1) PKU diagnosis and start of treatment after 7 years of age; 2) untreated plasma phenylalanine concentrations >/=1200 mumol/l; and 3) IQ >/=80. Literature search, checking reference lists, selection of articles, and extraction of data were performed by two independent researchers. RESULTS: In total, we identified 59 published cases of patients with late-diagnosed PKU and unexpected favorable outcome who met the inclusion criteria. Although all investigated patients had intellectual functioning within the normal range, at least 19 showed other neurological, psychological, and/or behavioral symptoms. CONCLUSIONS: Based on the present findings, the classical symptomatology of untreated or late-treated PKU may need to be rewritten, not only in the sense that intellectual dysfunction is not obligatory, but also in the sense that intellectual functioning does not (re)present the full picture of brain damage due to high plasma phenylalanine concentrations. Further identification of such patients and additional analyses are necessary to better understand these differences between PKU patients.

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Contains fulltext : 195728.pdf (publisher's version ) (Open Access), BACKGROUND: Phenylketonuria (PKU) is often considered as the classical example of a genetic disorder in which severe symptoms can nowadays successfully be prevented by early diagnosis and treatment. In contrast, untreated or late-treated PKU is known to result in severe intellectual disability, seizures, and behavioral disturbances. Rarely, however, untreated or late-diagnosed PKU patients with high plasma phenylalanine concentrations have been reported to escape from intellectual disability. The present study aimed to review published cases of such PKU patients. METHODS: To this purpose, we conducted a literature search in PubMed and EMBASE up to 8th of September 2017 to identify cases with 1) PKU diagnosis and start of treatment after 7 years of age; 2) untreated plasma phenylalanine concentrations >/=1200 mumol/l; and 3) IQ >/=80. Literature search, checking reference lists, selection of articles, and extraction of data were performed by two independent researchers. RESULTS: In total, we identified 59 published cases of patients with late-diagnosed PKU and unexpected favorable outcome who met the inclusion criteria. Although all investigated patients had intellectual functioning within the normal range, at least 19 showed other neurological, psychological, and/or behavioral symptoms. CONCLUSIONS: Based on the present findings, the classical symptomatology of untreated or late-treated PKU may need to be rewritten, not only in the sense that intellectual dysfunction is not obligatory, but also in the sense that intellectual functioning does not (re)present the full picture of brain damage due to high plasma phenylalanine concentrations. Further identification of such patients and additional analyses are necessary to better understand these differences between PKU patients.

Objective : Nitric oxide (NO) inhibits thrombus formation, vascular contraction, and smooth muscle cell proliferation. We investigated whether NO release is enhanced after endothelial NO synthase (eNOS) gene transfer in atherosclerotic human carotid artery ex vivo. Methods and Results : Western blotting and immunohistochemistry revealed that transduction enhanced eNOS expression; however, neither nitrite production nor NO release measured by porphyrinic microsensor was altered. In contrast, transduction enhanced NO production in non-atherosclerotic rat aorta and human internal mammary artery. In transduced carotid artery, calcium-dependent eNOS activity was minimal and did not differ from control conditions. Vascular tetrahydrobiopterin concentrations did not differ between the experimental groups.Treatment of transduced carotid artery with FAD, FMN, NADPH, L-arginine, and either sepiapterin or tetrahydrobiopterin did not alter NO release. Superoxide formation was similar in transduced carotid artery and control. Treatment of transduced carotid artery with superoxide dismutase (SOD), PEG-SOD, PEG-catalase did not affect NO release. Conclusions : eNOS transduction in atherosclerotic human carotid artery results in high expression without any measurable activity of the recombinant protein. The defect in the atherosclerotic vessels is neither caused by cofactor deficiency nor enhanced NO breakdown. Since angioplasty is performed in atherosclerotic arteries,eNOS gene therapy is unlikely to provide clinical benefit

Aromatic L-amino acid decarboxylase deficiency (AADCD) is a rare, autosomal recessive neurometabolic disorder that leads to a severe combined deficiency of serotonin, dopamine, norepinephrine and epinephrine. Onset is early in life, and key clinical symptoms are hypotonia, movement disorders (oculogyric crisis, dystonia, and hypokinesia), developmental delay, and autonomic symptoms. In this consensus guideline, representatives of the International Working Group on Neurotransmitter Related Disorders (iNTD) and patient representatives evaluated all available evidence for diagnosis and treatment of AADCD and made recommendations using SIGN and GRADE methodology. In the face of limited definitive evidence, we constructed practical recommendations on clinical diagnosis, laboratory diagnosis, imaging and electroencephalograpy, medical treatments and non-medical treatments. Furthermore, we identified topics for further research. We believe this guideline will improve the care for AADCD patients around the world whilst promoting general awareness of this rare disease. © 2016 The Author(s).

Contains fulltext : 170061.pdf (publisher's version ) (Open Access)

Item does not contain fulltext, We developed European guidelines to optimise phenylketonuria (PKU) care. To develop the guidelines, we did a literature search, critical appraisal, and evidence grading according to the Scottish Intercollegiate Guidelines Network method. We used the Delphi method when little or no evidence was available. From the 70 recommendations formulated, in this Review we describe ten that we deem as having the highest priority. Diet is the cornerstone of treatment, although some patients can benefit from tetrahydrobiopterin (BH4). Untreated blood phenylalanine concentrations determine management of people with PKU. No intervention is required if the blood phenylalanine concentration is less than 360 mumol/L. Treatment is recommended up to the age of 12 years if the phenylalanine blood concentration is between 360 mumol/L and 600 mumol/L, and lifelong treatment is recommended if the concentration is more than 600 mumol/L. For women trying to conceive and during pregnancy (maternal PKU), untreated phenylalanine blood concentrations of more than 360 mumol/L need to be reduced. Treatment target concentrations are as follows: 120-360 mumol/L for individuals aged 0-12 years and for maternal PKU, and 120-600 mumol/L for non-pregnant individuals older than 12 years. Minimum requirements for the management and follow-up of patients with PKU are scheduled according to age, adherence to treatment, and clinical status. Nutritional, clinical, and biochemical follow-up is necessary for all patients, regardless of therapy.

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Contains fulltext : 182674.pdf (publisher's version ) (Open Access), Phenylketonuria (PKU) is an autosomal recessive inborn error of phenylalanine metabolism caused by deficiency in the enzyme phenylalanine hydroxylase that converts phenylalanine into tyrosine. If left untreated, PKU results in increased phenylalanine concentrations in blood and brain, which cause severe intellectual disability, epilepsy and behavioural problems. PKU management differs widely across Europe and therefore these guidelines have been developed aiming to optimize and standardize PKU care. Professionals from 10 different European countries developed the guidelines according to the AGREE (Appraisal of Guidelines for Research and Evaluation) method. Literature search, critical appraisal and evidence grading were conducted according to the SIGN (Scottish Intercollegiate Guidelines Network) method. The Delphi-method was used when there was no or little evidence available. External consultants reviewed the guidelines. Using these methods 70 statements were formulated based on the highest quality evidence available. The level of evidence of most recommendations is C or D. Although study designs and patient numbers are sub-optimal, many statements are convincing, important and relevant. In addition, knowledge gaps are identified which require further research in order to direct better care for the future.

Contains fulltext : 170061.pdf (publisher's version ) (Open Access)

Item does not contain fulltext, We developed European guidelines to optimise phenylketonuria (PKU) care. To develop the guidelines, we did a literature search, critical appraisal, and evidence grading according to the Scottish Intercollegiate Guidelines Network method. We used the Delphi method when little or no evidence was available. From the 70 recommendations formulated, in this Review we describe ten that we deem as having the highest priority. Diet is the cornerstone of treatment, although some patients can benefit from tetrahydrobiopterin (BH4). Untreated blood phenylalanine concentrations determine management of people with PKU. No intervention is required if the blood phenylalanine concentration is less than 360 mumol/L. Treatment is recommended up to the age of 12 years if the phenylalanine blood concentration is between 360 mumol/L and 600 mumol/L, and lifelong treatment is recommended if the concentration is more than 600 mumol/L. For women trying to conceive and during pregnancy (maternal PKU), untreated phenylalanine blood concentrations of more than 360 mumol/L need to be reduced. Treatment target concentrations are as follows: 120-360 mumol/L for individuals aged 0-12 years and for maternal PKU, and 120-600 mumol/L for non-pregnant individuals older than 12 years. Minimum requirements for the management and follow-up of patients with PKU are scheduled according to age, adherence to treatment, and clinical status. Nutritional, clinical, and biochemical follow-up is necessary for all patients, regardless of therapy.

Item does not contain fulltext

Contains fulltext : 182674.pdf (publisher's version ) (Open Access), Phenylketonuria (PKU) is an autosomal recessive inborn error of phenylalanine metabolism caused by deficiency in the enzyme phenylalanine hydroxylase that converts phenylalanine into tyrosine. If left untreated, PKU results in increased phenylalanine concentrations in blood and brain, which cause severe intellectual disability, epilepsy and behavioural problems. PKU management differs widely across Europe and therefore these guidelines have been developed aiming to optimize and standardize PKU care. Professionals from 10 different European countries developed the guidelines according to the AGREE (Appraisal of Guidelines for Research and Evaluation) method. Literature search, critical appraisal and evidence grading were conducted according to the SIGN (Scottish Intercollegiate Guidelines Network) method. The Delphi-method was used when there was no or little evidence available. External consultants reviewed the guidelines. Using these methods 70 statements were formulated based on the highest quality evidence available. The level of evidence of most recommendations is C or D. Although study designs and patient numbers are sub-optimal, many statements are convincing, important and relevant. In addition, knowledge gaps are identified which require further research in order to direct better care for the future.

Item does not contain fulltext

Contains fulltext : 182674.pdf (publisher's version ) (Open Access), Phenylketonuria (PKU) is an autosomal recessive inborn error of phenylalanine metabolism caused by deficiency in the enzyme phenylalanine hydroxylase that converts phenylalanine into tyrosine. If left untreated, PKU results in increased phenylalanine concentrations in blood and brain, which cause severe intellectual disability, epilepsy and behavioural problems. PKU management differs widely across Europe and therefore these guidelines have been developed aiming to optimize and standardize PKU care. Professionals from 10 different European countries developed the guidelines according to the AGREE (Appraisal of Guidelines for Research and Evaluation) method. Literature search, critical appraisal and evidence grading were conducted according to the SIGN (Scottish Intercollegiate Guidelines Network) method. The Delphi-method was used when there was no or little evidence available. External consultants reviewed the guidelines. Using these methods 70 statements were formulated based on the highest quality evidence available. The level of evidence of most recommendations is C or D. Although study designs and patient numbers are sub-optimal, many statements are convincing, important and relevant. In addition, knowledge gaps are identified which require further research in order to direct better care for the future.

Contains fulltext : 170061.pdf (publisher's version ) (Open Access)

Item does not contain fulltext, We developed European guidelines to optimise phenylketonuria (PKU) care. To develop the guidelines, we did a literature search, critical appraisal, and evidence grading according to the Scottish Intercollegiate Guidelines Network method. We used the Delphi method when little or no evidence was available. From the 70 recommendations formulated, in this Review we describe ten that we deem as having the highest priority. Diet is the cornerstone of treatment, although some patients can benefit from tetrahydrobiopterin (BH4). Untreated blood phenylalanine concentrations determine management of people with PKU. No intervention is required if the blood phenylalanine concentration is less than 360 mumol/L. Treatment is recommended up to the age of 12 years if the phenylalanine blood concentration is between 360 mumol/L and 600 mumol/L, and lifelong treatment is recommended if the concentration is more than 600 mumol/L. For women trying to conceive and during pregnancy (maternal PKU), untreated phenylalanine blood concentrations of more than 360 mumol/L need to be reduced. Treatment target concentrations are as follows: 120-360 mumol/L for individuals aged 0-12 years and for maternal PKU, and 120-600 mumol/L for non-pregnant individuals older than 12 years. Minimum requirements for the management and follow-up of patients with PKU are scheduled according to age, adherence to treatment, and clinical status. Nutritional, clinical, and biochemical follow-up is necessary for all patients, regardless of therapy.

Urinary citrate is a potent inhibitor of calcium oxalate (CaOx) crystallization, but oral citrate has rarely been used in patients with primary hyperoxaluria (PH). We studied the effect of sodium citrate administration (0.1-0.15 g/kg/day) on urinary citrate excretion and CaOx saturation in seven paediatric patients and the clinical response to long-term treatment (average 4 years) in five patients. Urinary citrate increased from 0.73 to 2.54 mmol/24h/l.73 m2 and urinary saturation for CaOx (calculated by equil 2) decreased from 11.41 to 6.79 (for both, p<0.02). Long-term administration of alkali citrate [0.15 g (0.5 mmol)/kg/day] resulted in stable or improved renal function in three and slow deterioration in two partially non-compliant patients. Alkali citrate is effective in patients with PH

This chapter will deal with analytical procedures for 5-methyltetrahydrofolic acid (5MTHF) in cerebrospinalfluid (CSF) and serum. Folic acid is a water-soluble vitamin that functions as a one-carbon donor in various metabolic cycles. It is involved in the biosynthesis of thymidylates and purines, methionine synthesis via homocysteine remethylation, the methylation of phospholipids, the interconversion of serine and glycine, and the metabolism of histidine and formate.It is therefore essential for growth, reproduction, and maintenance of normal body function. The natural form is referred to as folate; it consists mainly of 5MTHF and 10-formyltetrahydrofolate in their polyglutamate derivatives [1]. 5MTHF is the active one-carbon donor. It is transported through the blood–brain barrier to serve for a number of reactions in the centralnervous system. Serum folate deficiency is known to be associated with megaloblastic anemia, high blood levels of homocysteine, and neural tube defect in newborns as a result of folate shortage of the mother[2, 3]. Cerebral folate deficiency (CFD) is a recently recognized neurological disorder found in several children with psychomotor retardation, spastic paraplegia, cerebellar ataxia, and dyskinesia.These patients have very low 5MTHF in their CSF, normal blood folates [4, 5], and some patients display a high titer of folate receptor-blocking autoantibodies[6]. CFD is further associated with the following inherited metabolic disorders: 5,10-methylen-tetrahydrofolate reductase (MTHFR) deficiency [7], 3-phosphoglycerate dehydrogenase (PGDH) deficiency [8], dihydropteridine reductase (DHPR) deficiency [9], as well as with Rett syndrome [10], and Aicardi-Goutières Syndrome [11]. Furthermore, folate deficiency may be associated with congenital folate malabsorption, severe malnutrition, and formiminotransferase deficiency. 5MTHF was initially measured by microbiological and radioisotope dilution as-say [12, 13], and later by high-pressure liqui

Measurement of oxalate in urine is important for diagnosis of primary hyperoxaluria and the secondary forms resulting from excessive intake or abnormal intestinal absorption of oxalate. Determination of glycolic acid is essential for diagnosis of primary hyperoxaluria type I (PH I), caused by low or absent activity of the liver-specific peroxisomal alanine:glyoxylate aminotransferase. Primary hyperoxaluria type II (PH II) is caused by low or absent activity D-glycerate dehydrogenase and hydroxypyruvate reductase activity, leading to elevated urinary excretion of both oxalate and L-glyceric acid. Ion chromatography HPLC is the method of choice the quantification of oxalate, glycolate, and glycerate and use of urinary filter spots is a practical alternative approach for the collection and safe transport of samples to be analyzed for many metabolic disorders.