Quantitative DNA Methylation Analysis and Epigenotype-Phenotype Correlations in Taiwanese Patients with Silver-Russell Syndrome.

Background: Silver-Russell syndrome (SRS; OMIM #180860) is a clinically and genetically heterogeneous imprinting disorder characterized by prenatal and postnatal growth failure. The aim of this study was to identify the epigenotype-phenotype correlations in these patients using quantitative DNA methylation analysis. Methods: One hundred and eighty-three subjects clinically suspected of having SRS were referred for diagnostic testing by the methylation profiling of H19-associated imprinting center (IC) 1 and imprinted PEG1/MEST regions using methylation-specific high-resolution melting analysis and methylation quantification with the MassARRAY assay. Correlations between quantitative DNA methylation status and clinical manifestations of the subjects according to the Netchine-Harbison (N-H) clinical scoring system for SRS were analyzed. Results: Among the 183 subjects, 90 had a clinical diagnosis of SRS [N-H score ≥ 4 (maximum = 6)] and 93 had an SRS score < 4. Molecular lesions were detected in 41% (37/90) of the subjects with a clinical diagnosis of SRS, compared with 3% (3/93) of those with an N-H score < 4. The IC1 methylation level was negatively correlated with the N-H score. The molecular diagnosis rate was positively correlated with the N-H score. Thirty-one subjects had IC1 hypomethylation (IC1 methylation level <35% by the MassARRAY assay), seven had maternal uniparental disomy 7, and two had pathogenic copy number variants. Among the 90 subjects with an N-H score ≥ 4, the IC1 methylation level was significantly different between those with or without some clinical SRS features, including birth length ≤ 10th centile, relative macrocephaly at birth, normal cognitive development, body asymmetry, clinodactyly of the fifth finger, and genital abnormalities. Conclusions: This study confirmed the suitability of the N-H clinical scoring system as clinical diagnostic criteria for SRS. Quantitative DNA methylation analysis using the MassARRAY assay can improve the detection of epigenotype-phenotype correlations, further promoting better genetic counseling and multidisciplinary management for these patients.

Congenital generalized lipodystrophy in Taiwan.

BACKGROUND: Congenital generalized lipodystrophy (CGL) is a rare disorder characterized by scarce adipose tissue. This disease is distributed worldwide, but little is known about these patients in the Chinese population. Here, we delineate the phenotype and prognosis of CGL in our cohort. METHODS: Patients diagnosed with CGL from 8 medical centers were reviewed. The initial presentation, laboratory findings, and molecular testing were retrospectively analyzed. RESULTS: A total of 16 patients were analyzed, and the current median age was 3.5 years (range, 9 months-17.5 years). In all patients, molecular results confirmed BSCL2 mutation. c.782dupG (p.Ile262Hisfs*12) was the most common genotype identified. All patients had triangular faces and muscular hypertrophy. In addition, 75% presented with hepatomegaly, 19% had cardiomegaly, and 44% exhibited acanthosis nigricans. Developmental delay was noted in 5 out of 9 patients (56%) with a median developmental quotient (DQ)/intelligence quotient (IQ) of 61. Thirteen patients (81.3%) had high triglyceride levels. Eight patients received leptin analysis, and 7 of them (88%) had low leptin levels. One patient exclusively received a lipid-lowering drug, 4 patients were exclusively placed on a fat-restricted diet, 5 patients were administered combination therapy, and 5 patients received no treatment. Three patients (19%) who developed diabetes mellitus received both oral hypoglycemic agents and insulin. Three patients (19%) experienced loss of ambulation and died prematurely. CONCLUSION: Our findings highlight the uniqueness of the genotype and phenotype in our cohort. Further long-term surveillance for comorbidities is necessary for early detection and management of these patients.

Functional independence of Taiwanese children with Prader-Willi syndrome.

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.

3-O-methyldopa levels in newborns: Result of newborn screening for aromatic l-amino-acid decarboxylase deficiency.

BACKGROUND: The diagnosis of aromatic l-amino-acid decarboxylase (AADC) deficiency is often delayed because a cerebrospinal fluid analysis is required to detect a neurotransmitter deficiency. We here demonstrated that an elevated concentration of l-dopa metabolite 3-O-methyldopa (3-OMD) in dried blood spots could be integrated into newborn screening program to precisely predict AADC deficiency. METHODS: After obtaining parental consent, an additional spot was punched from newborn filter paper, eluted, cleaned, and analyzed by tandem mass spectrometry. Newborns with a 3-OMD concentration exceeding 500ng/mL were referred for confirmatory testing. RESULTS: From September 2013 to December 2015, 127,987 newborns were screened for AADC deficiency. The mean 3-OMD concentration in these newborns was 88.08ng/mL (SD=27.74ng/mL). Four newborns exhibited an elevated 3-OMD concentration (range, 939-3241ng/mL). All four newborns were confirmed to carry two pathologic DDC mutations, indicating an incidence of AADC deficiency of 1:32,000. During the follow-up period, three patients developed typical symptoms of AADC deficiency. Among 16 newborns with mildly elevated 3-OMD levels, six were heterozygous for the DDC IVS6+4A>T mutation. CONCLUSION: Newborn screening of AADC deficiency was achieved with a 100% positive-predictive rate. An association for gestational age could be further elucidated.

Outcome of early-treated type III Gaucher disease patients.

Recombinant human acid ß-glucosidase GBA (rhGBA) infusion is an effective therapy for non-neuropathic (type I) Gaucher disease (GD), but its effect on subacute neuropathic (type III) GD is still controversial. The most common genotype for type III GD is homozygous c.1448T>C (p.L444P) mutation, and in this study, we treated seven such patients starting from an early age (median 2.1 years; range 1-2.9 years). Before the start of treatment, all patients presented hepatosplenomegaly, anemia, and thrombocytopenia, but with no neurological signs. Normalization of hemoglobin levels and platelet numbers was achieved in all patients in one year. However, after a median treatment period of 7.6 years (2.2-12.0 years), two patients developed horizontal gaze palsy, one had seizures, four demonstrated mental retardation, and five showed kyphosis. Moreover, lymphadenopathy in the neck, thorax, or abdomen was observed in four patients. Therefore, the progression of neurological symptoms in these patients probably reflected the neurologic natural history of type III GD. Residual somatic symptoms, including kyphosis and lymphadenopathy, may be more common than what we thought. An additional treatment will be necessary to improve the outcome of type III GD.

Spectrum of PHEX Mutations and FGF23 Profiles in a Taiwanese Cohort With X-Linked Hypophosphatemia Including 102 Patients.

BACKGROUND/AIM: X-linked hypophosphatemia (XLH), the most common form of hereditary rickets, results from loss-of-function mutations in the phosphate-regulating PHEX gene. Elevated fibroblast growth factor 23 (FGF23) contributes to hypophosphatemia in XLH. This study aimed to characterize PHEX variants and serum FGF23 profiles in Taiwanese patients with XLH. PATIENTS AND METHODS: We retrospectively reviewed the records of 102 patients clinically suspected of having hypophosphatemic rickets from 2006 to 2022. Serum intact Fibroblast growth factor-23 (iFGF23) levels were measured on clinic visit days. PHEX mutations were identified using Sanger sequencing, and negative cases were analyzed using whole-exome sequencing. RESULTS: The majority (92.1%) of patients exhibited elevated FGF23 compared with normal individuals. Among 102 patients, 44 distinct PHEX mutations were identified. Several mutations recurred in multiple unrelated Taiwanese families. We discovered a high frequency of novel PHEX mutations and identified variants associated with extreme FGF23 elevation and tumorigenesis. CONCLUSION: Our findings revealed the PHEX genotypic variants and FGF23 levels in Taiwanese patients with XLH. These results are crucial given the recent approval of burosumab, a monoclonal FGF23 antibody, for XLH therapy. This study provides key insights into the clinical management of XLH in Taiwan.

Temporal changes of urinary oxidative metabolites of di(2-ethylhexyl)phthalate after the 2011 phthalate incident in Taiwanese children: findings of a six month follow-up.

A major incident involving phthalates-contaminated foodstuffs occurred in Taiwan in May 2011, leading to the quick removal of tainted food items from store shelves. We investigated changes in urinary oxidative di(2-ethylhexyl)phthalate (DEHP) metabolites, our proxy for exposure to DEHP-tainted foodstuffs in children ≤10 years, during the six months following withdrawal of the tainted food. Our hospital screened 60 possibly exposed children between May and June 2011. The children's food intake information was collected, and they were administered one-spot urine samples at baseline and at the two and six month follow-ups. All three samples were measured for four oxidative DEHP metabolites, mono-(2-ethyl-5-hydroxyhexyl) phthalate (5OH-MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (5oxo-MEHP), mono-(2-ethyl-5-carboxypentyl) phthalate (5cx-MEPP), and mono-(2-carboxymethylhexyl) phthalate (2cx-MMHP) by triple quadrupole liquid chromatography tandem mass spectrometry. Fifty-two children had been exposed. After excluding those without a full set of urine samples or adequate food intake information, 23 exposed children were studied. We found significantly positive correlations between DEHP daily intake and urinary 5OH-MEHP, 5oxo-MEHP, and 5cx-MEPP (p < 0.05). At the six month follow-up, all four metabolite concentrations had significantly decreased compared to the baseline. In conclusion, urinary DEHP metabolites decreased progressively in children after tainted food withdrawal, indicating that the main sources of phthalate contamination for children had been successfully controlled.

CD40 Gene polymorphisms associated with susceptibility and coronary artery lesions of Kawasaki disease in the Taiwanese population.

BACKGROUND: Kawasaki disease (KD) is characterized by systemic vasculitis of unknown etiology. Our previous studies showed expression of CD40 ligand on CD4+ T cells correlated to the coronary artery lesion (CAL) and disease progress in KD. Other studies from Japan suggested the role of CD40L in the pathogenesis of CAL, and this might help explain the excessive number of males affected with KD but cannot be reproduced by Taiwanese population. This study was conducted to investigate the CD40 polymorphism in KD and CAL formation. METHODS: A total of 950 subjects (381 KD patients and 569 controls) were investigated to identify 2 tagging single-nucleotide polymorphisms (tSNPs) of CD40 (rs4810485 and rs1535045) by using the TaqMan allelic discrimination assay. RESULTS: A significant association was noted with regards to CD40 tSNPs (rs1535045) between controls and KD patients (P = 0.0405, dominant model). In KD patients, polymorphisms of CD40 (rs4810485) showed significant association with CAL formation (P = 0.0436, recessive model). Haplotype analysis did not yield more significant results between polymorphisms of CD40 and susceptibility/disease activity of KD. CONCLUSIONS: This study showed for the first time that polymorphisms of CD40 are associated with susceptibility to KD and CAL formation, in the Taiwanese population.

Lack of association between ORAI1/CRACM1 gene polymorphisms and Kawasaki disease in the Taiwanese children.

OBJECTIVE: Kawasaki disease (KD) is characterized by systemic vasculitis of an unknown cause. A previous study has indicated that a polymorphism of the inositol 1,4,5-trisphosphate 3-kinase C (ITPKC) gene is involved in the susceptibility to KD. ORAI (also known as CRACM1) is one of the components of store-operated calcium channels involved in regulating immune and inflammatory reactions. This study was conducted to investigate if polymorphisms in ORAI1/CRACM1, a gene downstream from ITPKC, are associated with KD susceptibility and clinical outcomes. MATERIALS AND METHODS: A total of 1,056 subjects (341 KD patients and 715 controls) were investigated to identify five tagging single nucleotide polymorphisms (tSNPs) in ORAI1/CRACM1 (rs12313273, rs6486795, rs7135617, rs12320939, and rs712853) by using the TaqMan Allelic Discrimination assay. RESULTS: No significant associations between genotype and allele frequency of the five ORAI1/CRACM1 tSNPs were observed in the KD patients and controls. In KD patients, no significant associations between ORAI1/CRACM1 polymorphisms and coronary artery lesion (CAL) formation or intravenous immunoglobulin (IVIG) treatment response were observed. The results from haplotype analysis were insignificant. CONCLUSIONS: This study showed for the first time that ORAI1/CRACM1 polymorphisms are not associated with KD susceptibility, CAL formation, or IVIG treatment response in the Taiwanese population.

Low penetrance of retinoblastoma for p.V654L mutation of the RB1 gene.

BACKGROUND: Retinoblastoma is caused by compound heterozygosity or homozygosity of retinoblastoma gene (RB1) mutations. In germline retinoblastoma, mutations in the RB1 gene predispose individuals to increased cancer risks during development. These mutations segregate as autosomal dominant traits with high penetrance (90%). METHODS: We screened 30 family members from one family using high resolution melting assay and DNA direct sequencing for mutations in the RB1 gene. We evaluate the phenotype and penetrance of germline mutations of the RB1 gene in a large Taiwanese family. RESULTS: The molecular analysis and clinical details of this family showed phenotypic variability associated with the p.V654L mutation in exon 19 of the RB1 gene in 11 family members. The phenotype varied from asymptomatic to presence of a unilateral tumor. Only four individuals (2 males and 2 females) developed unilateral retinoblastoma, which resulted in calculated low penetrance of 36% (4/11). The four individuals with retinoblastoma were diagnosed before the age of three years. None of their relatives exhibited variable severity or bilateral retinoblastoma. CONCLUSIONS: The diseased-eye ratio for this family was 0.36, which is lower than current estimates. This suggests that the RB1 p.V654L mutation is a typical mutation associated with low penetrance.

Polymorphisms of transforming growth factor-ß signaling pathway and Kawasaki disease in the Taiwanese population.

Kawasaki disease (KD) is a systemic vasculitis associated with cardiovascular symptom. A previous study in the European descent has indicated that genetic variants of the transforming growth factor-ß (TGF-ß) pathway are involved in the KD susceptibility and clinical status. This study was conducted to investigate if polymorphisms in TGF-ß signaling pathway are associated with KD susceptibility, and the coronary artery lesion formation. A total of 950 subjects (381 KD patients and 569 controls) were investigated to identify 12 single-nucleotide polymorphisms in the TGF-ß signaling pathway (rs2796817, rs10482751, rs2027567, rs12029576, rs11466480, rs4776338, rs12901071, rs7162912, rs1438386, rs6494633, rs12910698 and rs4776339) by using TaqMan Allelic Discrimination assay. Our results indicated that rs1438386 in the SMAD3 is significantly associated with the susceptibility of KD. Additionally, both haplotypes of TGFß2 and SMAD3 were also associated with the risk of KD. This study showed that genetic polymorphisms in TGF-ß signaling pathway are associated with KD susceptibility, but not coronary artery lesions formation, or intravenous immunoglobulin treatment response in the Taiwanese population.

Monitoring Adherence Rate to Growth Hormone Therapy and Growth Outcomes in Taiwanese Children Using Easypod Connect: Observational Study.

BACKGROUND: Adherence to growth hormone therapy is difficult to detect reliably. Devices such as easypod have been developed for electronic recording of injections. The easypod connect observational study (ECOS) was an open-label, observational, multinational, phase IV study conducted in 24 countries around the world. The final results from ECOS in the Taiwanese cohort are reported in this paper. OBJECTIVE: This study aimed to evaluate the adherence and long-term outcomes of growth hormone therapy in pediatric subjects using the easypod electromechanical device. METHODS: Subjects (aged 2-18 years or >18 years without fusion of growth plates) who received Saizen (recombinant human growth hormone, somatropin) via the easypod device were enrolled in this study. The primary objective was to assess the level of adherence in subjects receiving Saizen via easypod. RESULTS: In Taiwan, a total of 35 and 13 children fulfilled the criteria of full analysis set and complete analysis set, respectively. The mean (SD) age of the complete analysis set was 12.08 (2.72) years. All subjects were growth hormone-naïve, with 38% (5/13) females. The mean adherence rates of 13 subjects were 87.6% at 3 months and 84.3% at 6 months, that of 8 subjects was 81.0% at 9 months, and that of 4 subjects was 91.6% at 1 year. After 1 year of treatment, subjects had a median (Q1:Q3) change in height SD score of 0.30 (0.06:0.48), median height velocity of 6.50 (4.33:8.24) cm/year, and median change in height velocity SD score of 1.81 (-0.04:3.52). CONCLUSIONS: With the easypod device, patients with inadequate adherence and poor response to treatment can be identified. Adherence to growth hormone therapy administered via easypod was generally high in the first year of treatment but the adherence gradually decreased over time. Overall, growth outcomes after 1 year indicated a positive growth response to growth hormone treatment. Future efforts should be focused on personalized management of adherence by using the easypod system.

Altered Pattern of Macrophage Polarization as a Biomarker for Severity of Childhood Asthma.

PURPOSE: Asthma causes a substantial morbidity and mortality burden in children and the pathogenesis of childhood asthma is not completely understood. Macrophages are heterogeneous with divergent M1/M2 polarization phenotypes in response to various stimulations during the inflammatory process. We aimed to investigate the pattern of macrophage polarization and its association with severity and exacerbation in asthmatic children. PATIENTS AND METHODS: Normal and asthmatic children aged 4-18 years were enrolled for 12 months. Children with asthma were further subgrouped according to their severity and the requirement for hospitalization during exacerbations. Clinical data were obtained from medical records. Peripheral blood samples were collected to analyze macrophage polarization, including M1, M2, and subsets, by flow cytometry. RESULTS: Fifty-one asthmatic cases and 27 normal controls were included in this study. The level of PM-2K+CD14+ but not PM-2K+CD14- was decreased in asthmatic children. The levels of M2a (CCR7-CXCR1+), M2b (CCR7-CD86+), and M2c (CCR7-CCR2+) subsets, but not M1 (CCR7+CD86+), were increased in asthmatic children. The levels of M1 were decreased, but the levels of M2c were increased, in children with moderate asthma compared to those with mild asthma. The levels of PM-2K+CD14+ cells and M1 subsets were decreased, but the M2c subset cells were increased in asthmatic children requiring hospitalization during exacerbations. CONCLUSION: Macrophage polarization may be involved in the pathogenesis of childhood asthma and is a potential biomarker of childhood asthma disease severity.

Epigenotype, Genotype, and Phenotype Analysis of Taiwanese Patients with Silver-Russell Syndrome.

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.

Comparing the Southern blot method and polymerase chain reaction product analysis for chimeric RCCX detection in CYP21A2 deficiency.

The 3.2-kb TaqI-produced fragment of the CYP21A1P pseudogene and the 3.7-kb TaqI-produced fragment of the functional CYP21A2 gene exist on chromosome 6p21.3. We used the polymerase chain reaction (PCR) product and Southern blot method with TaqI endonuclease digestion to identify a chimeric RCCX module in two unrelated patients with congenital adrenal hyperplasia (CAH). After TaqI cleavage, the PCR product analysis revealed that patient 1 with the chimeric CYP21A1P/CYP21A2 gene in one allele and IVS2-12A/C>G in combination with the 707-714del mutation in the other allele produced a configuration of 3.2- and 2.4-kb fragments. Patient 2, who carried IVS2-12A/C>G in combination with the 707-714del mutation in one allele and the chimeric TNXA/TNXB gene in the other allele, presented with 3.2- and 2.3-kb fragments. However, Southern blot analysis showed that patients 1 and 2 produced 3.2-, 2.4-, and 2.5-kb fragments. We conclude that the chimeric CYP21A1P/CYP21A2 gene, IVS2-12A/C>G in combination with the 707-714del mutation, and the chimeric TNXA/TNXB gene cannot be distinguished by the Southern blot method. Conversely, the chimeric TNXA/TNXB gene was identified in the PCR product analysis due to the appearance of the 2.37-kb fragment, which indicates the occurrence of the chimeric TNXA/TNXB formation extending to the boundary of TNXA in the RCCX region.

FOXL2 mutations in Taiwanese patients with blepharophimosis, ptosis, epicanthus inversus syndrome.

BACKGROUND: Blepharophimosis, ptosis, epicanthus inversus syndrome (BPES) is an autosomal dominant developmental disorder that includes an eyelid malformation associated with (type I) or without (type II) premature ovarian failure (POF). Mutations in the forkhead transcription factor 2 (FOXL2) gene, a member of winged/forkhead transcription factor family, are responsible for both types of BPES. The purpose of this study was to identify mutations in FOXL2 in Taiwanese patients with BPES. METHODS: The karyotype and genomic DNA was prepared from the leukocytes of peripheral venous blood samples. The coding and flanking region sequences of FOXL2 were analyzed by directed or cloning sequencing. RESULTS: The karyotypes of these patients did not show significant variation, especially on the 3q23 region. Two mutations in FOXL2 were identified in two familial cases. One was c.855-871dup (17-bp insertion) associated with POF. The other was c.384G>A (TGG>TGA), a novel mutation that resulted in non-sense changes of the encoded protein, i.e., p.W128X. CONCLUSIONS: Our results expand the spectrum of FOXL2 mutations and confirm the mutation hotspot in FOXL2 in Taiwanese BPES patients.

Impaired glucose homeostasis and a novel HLCS pathogenic variant in holocarboxylase synthetase deficiency: a report of two cases and brief review.

Objectives Holocarboxylase synthetase deficiency (HCSD) (OMIM #253270) is a rare inborn error of metabolism with an estimated annual incidence of 1 in 200,000 people. Typical manifestations of HCSD include eczema, alopecia, lactic acidosis and hyperammonemia. Diagnosis is made through genetic analysis. Case presentation Patient 1 was a 7-year-old girl with normal growth and development, presenting with severe hypoglycemia and metabolic acidosis. Her family reported that she was diagnosed as having ketotic hypoglycemia; she had five episodes of hypoglycemia and metabolic acidosis in past 4 years when her oral intake decreased during acute illness. Patient 2 was a 6-month-old female infant with normal growth and development, presenting with progressive generalized eczema and metabolic acidosis for the first time. We found that they both had hyperammonemia, hyperlactatemia, hyperketonemia, organic acids detected in urine and elevated C5OH acylcarnitine level by tandem mass spectrometry. HLCS gene analysis showed a homozygous pathogenic variant p.V363D in patient 1 and a pathogenic variant p.R508W compound with a novel splice site pathogenic variant c.2010-1G>A in patient 2. They have been on biotin treatment (10 mg/day for both of them) for more than 2 years and no more symptoms have occurred. Conclusions HCSD is a rare disease, and it can be fatal if severe metabolic acidosis occurs without timely management. Once the diagnosis is made, most of the patients with HCSD have good prognosis and normal life expectancy with biotin treatment.

Survival and diagnostic age of 175 Taiwanese patients with mucopolysaccharidoses (1985-2019).

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.

The gene founder effect of two spontaneous mutations in ethnic Chinese (Taiwanese) CAH patients with 21-hydroxylase deficiency.

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.

Incidence of the mucopolysaccharidoses in Taiwan, 1984-2004.

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.