Atypical phenotypes and novel OCRL variations in southern Chinese patients with Lowe syndrome.

BACKGROUND: Lowe syndrome is characterized by the presence of congenital cataracts, psychomotor retardation, and dysfunctional proximal renal tubules. This study presents a case of an atypical phenotype, investigates the genetic characteristics of eight children diagnosed with Lowe syndrome in southern China, and performs functional analysis of the novel variants. METHODS: Whole-exome sequencing was conducted on eight individuals diagnosed with Lowe syndrome from three medical institutions in southern China. Retrospective collection and analysis of clinical and genetic data were performed, and functional analysis was conducted on the five novel variants. RESULTS: In our cohort, the clinical symptoms of the eight Lowe syndrome individuals varied. One patient was diagnosed with Lowe syndrome but did not present with congenital cataracts. Common features among all patients included cognitive impairment, short stature, and low molecular weight proteinuria. Eight variations in the OCRL gene were identified, encompassing three previously reported and five novel variations. Among the novel variations, three nonsense mutations were determined to be pathogenic, and two patients harboring novel missense variations of uncertain significance exhibited severe typical phenotypes. Furthermore, all novel variants were associated with altered protein expression levels and impacted primary cilia formation. CONCLUSION: This study describes the first case of an atypical Lowe syndrome patient without congenital cataracts in China and performs a functional analysis of novel variants in the OCRL gene, thereby expanding the understanding of the clinical manifestations and genetic diversity associated with Lowe syndrome.

Biochemical and molecular analysis of pediatric patients with metachromatic leukodystrophy in South China: functional characterization of five novel ARSA variants.

Metachromatic leukodystrophy (MLD) is a rare hereditary neurodegenerative disease caused by deficiency of the lysosomal enzyme arylsulfatase A (ARSA). This study described the clinical and molecular characteristics of 24 Chinese children with MLD and investigated functional characterization of five novel ARSA variants. A retrospective analysis was performed in 24 patients diagnosed with MLD at Guangzhou Women and Children's Medical Center in South China. Five novel mutations were further characterized by transient expression studies. We recruited 17 late-infantile, 3 early-juvenile, 4 late-juvenile MLD patients. In late-infantile patients, motor developmental delay and gait disturbance were the most frequent symptoms at onset. In juvenile patients, cognitive regression and gait disturbance were the most frequent chief complaints. Overall, 25 different ARSA mutations were identified with 5 novel mutations.The most frequent alleles were p.W320* and p.G449Rfs. The mutation p.W320*, p.Q155=, p.P91L, p.G156D, p.H208Mfs*46 and p.G449Rfs may link to late-infantile type. The novel missense mutations were predicted damaging in silico. The bioinformatic structural analysis of the novel missense mutations showed that these amino acid replacements would cause severe impairment of protein structure and function. In vitro functional analysis of the six mutants, showing a low ARSA enzyme activity, clearly demonstrated their pathogenic nature. The mutation p.D413N linked to R alleles. In western blotting analysis of the ARSA protein, the examined mutations retained reduced amounts of ARSA protein compared to the wild type. This study expands the spectrum of genotype of MLD. It helps to the future studies of genotype-phenotype correlations to estimate prognosis and develop new therapeutic approach.

Assessment of the diagnostic value of serum ceruloplasmin for Wilson's disease in children.

BACKGROUND: Serum ceruloplasmin is one of the major diagnostic parameters for Wilson's disease (WD). Age and gender difference of serum ceruloplasmin remain controversy. This study aims to assess diagnostic value of serum ceruloplasmin level for WD in children up to age of 15 years. METHODS: Serum ceruloplasmin levels were measured in 317 WD patients, 21 heterozygotes, 372 healthy control children and 154 non-WD patients with other liver diseases. Receiver operating characteristic (ROC) curve was used to determine the diagnostic accuracy of serum ceruloplasmin for WD in children. RESULTS: Among healthy controls, serum ceruloplasmin level was slightly low in the infants younger than 6 months, and then maintained from 26 to 33 mg/dl after age of 6 months. A total of 8.1% of healthy children had levels of serum ceruloplasmin < 20 mg/dL. Serum ceruloplasmin level was 5.7 ± 4.7 mg/dl in WD patients, and 25.6 ± 5.9 mg/dl in heterozygous carriers. Only 1.9% of WD patients had serum ceruloplasmin levels > 20 mg/dL. Serum ceruloplasmin levels had gender difference, being higher in healthy boys than healthy girls, and higher in asymptomatic WD boys than asymptomatic WD girls (p < 0.01, p < 0.05). Serum ceruloplasmin levels also presented genotypic difference. WD patients with R778L homozygotes exhibited lower levels of serum ceruloplasmin than the patients without R778L (p < 0.05). The ROC curve revealed that serum ceruloplasmin level, at a cutoff value of 16.8 mg/dL, had the highest AUC value (0.990) with a sensitivity of 95.9% and a specificity of 93.6%. CONCLUSIONS: Serum ceruloplasmin is one of sensitive diagnostic biomarkers for WD in children. Gender and genotypic difference of serum ceruloplasmin level should be considered. The cutoff value of serum ceruloplasmin level < 16.8 mg/dL may provide the highest accuracy for diagnosis of WD in children.

A very rare case report of glycogen storage disease type IXc with novel PHKG2 variants.

BACKGROUND: Pathogenic mutations in the PHKG2 are associated with a very rare disease-glycogen storage disease IXc (GSD-IXc)-and are characterized by severe liver disease. CASE PRESENTATION: Here, we report a patient with jaundice, hypoglycaemia, growth retardation, progressive increase in liver transaminase and prominent hepatomegaly from the neonatal period. Genetic testing revealed two novel, previously unreported PHKG2 mutations (F233S and R320DfsX5). Functional experiments indicated that both F223S and R320DfsX5 lead to a decrease in key phosphorylase b kinase enzyme activity. With raw cornstarch therapy, hypoglycaemia and lactic acidosis were ameliorated and serum aminotransferases decreased. CONCLUSION: These findings expand the gene spectrum and contribute to the interpretation of clinical presentations of these two novel PHKG2 mutations.

Clinical features and outcomes of 31 children with congenital hypothyroidism missed by neonatal screening.

OBJECTIVE: To investigate the clinical features and outcomes of children with congenital hypothyroidism (CH) missed by neonatal screening. METHODS: The clinical and laboratory date of 31 children with CH missed by neonatal screening from February 2015 to February 2022 in Guangzhou Women and Children's Medical Center were retrospectively analyzed. Whole-exome high-throughput sequencing analysis was performed in 17 patients. RESULTS: Among the 31 patients, 19 cases (61.3%) were preterm, 12 cases (38.7%) were term neonates. The median value of gestation age was 36 (26-40) weeks, birth weight was 2.35 (0.75-3.70) kg, diagnosed age was 20 d (7 d-4 years), dry blood spot thyrotropin was 4.18 (0.34-8.97) mU/L. Nine cases (29.0%) were same-sex twins and 4 cases (12.9%) had a family history of hypothyroidism. The initial clinical symptoms were growth retardation in 11 cases (35.5%), prolonged jaundice in 7 cases (22.6%), short stature, abdominal distension, fetal edema and goiter in 1 case (3.2%), respectively. Genetic analysis of the 17 children showed that DUOX2 gene mutations were detected in 10 cases (6 cases with biallelic mutations and 4 cases with monoallelic mutations), of whom 3 had a family history of hypothyroidism. A total of 22 patients were reevaluated at the age of 2-3 years, of whom 17 cases (77.3%) were transient CH and 5 cases (22.7%) were permanent CH. Among the 10 cases with DUOX2 gene mutations, 6 cases were transient CH, 1 case was permanent CH, and 3 cases (< 3 years old) were still under treatment with L-thyroxine. CONCLUSIONS: False negative results on neonatal screening for CH often occurs in preterm birth, low birth weight, same-sex twins, family history of hypothyroidism, and DUOX2 defects are the common molecular pathogenesis, most of whom are transient CH. Thyroid function should be evaluated in time for children with unexplained slow growth and delayed jaundice regression.

Screening for neonatal inherited metabolic disorders by tandem mass spectrometry in Guangzhou.

To analyze the screening results for inherited metabolic disorders (IMD) in newborns by tandem mass spectrometry (MS/MS) in Guangzhou.A total of 272 117 newborns in Guangzhou from Jan 2015 to Dec 2020 were screened for IMD by MS/MS in Guangzhou Newborn Screening Center. When the primary screening was positive, the newborns and their mothers were recalled. For those with positive in re-examination, the biochemical and related genetic analysis were required for confirmation. The screening results, clinical characteristics and outcomes of the confirmed cases were retrospectively analyzed and the performance was optimized. Among 272 117 neonates, 1808 (0.66%) cases were positive in primary screening, and 1738 cases (96.13%) were recalled for review. The median clinical diagnosis time was 15 d after birth. A total of 79 cases of IMD were diagnosed, including 23 with aminoacidopathy, 17 with disorder of organic acid metabolism and 39 with fatty acid oxidation disorders, involving 21 diseases. The incidence rate was 1/3444 in newborns, and the positive predictive value of 4.5%. Four false negative cases were found, all of them were citrin deficiency. The common diseases were primary carnitine deficiency (26.6%), methylmalonic aciduria (12.7%) and phenylalanine hydroxylase deficiency (11.4%). The mothers of 32 cases were confirmed, including 30 cases of primary carnitine deficiency, 1 case of isobutyl-coenzyme A dehydrogenase deficiency and 1 case of 3-methylcromaryl coenzyme A carboxylase deficiency. The detection rate was 1/2451 in total population. During the follow-up, most patients remain asymptomatic, except for 5 severe cases who died early (1 case of maple syrup urine disease, 2 cases of isolated methylmalonic acidurmia, and 2 cases of carnitine-acylcarnitine translocase deficiency); and 10 cases of organic acid metabolism disorders developed mild psychomotor developmental retardation. After optimizing the screening indicators, the number of initial screening positives dropped to 903, and the positive predictive value increased to 9.1%, and no confirmed cases were missed. The incidence rate of fatty acid oxidation disorders is high in Guangzhou. A variety of IMD can be effectively screened out by MS/MS, and the screening performance can be improved by optimizing screening indicators.

Distinct severity of phenotype in Hajdu-Cheney syndrome: a case report and literature review.

BACKGROUND: Hajdu-Cheney syndrome (HCS) is a rare inherited skeletal disorder caused by pathogenic mutations in exon 34 of NOTCH2. Its highly variable phenotypes make early diagnosis challenging. In this paper, we report a case of early-onset HCS with severe phenotypic manifestations but delayed diagnosis. CASE PRESENTATION: The patient was born to non-consanguineous, healthy parents of Chinese origin. She presented facial anomalies, micrognathia and skull malformations at birth, and was found hearing impairment, congenital heart disease and developmental delay during her first year of life. Her first visit to our center was at 1 year of age due to cardiovascular repair surgery for patent ductus arteriosus (PDA) and ventricular septal defect (VSD). Skull X-ray showed wormian bones. She returned at 7 years old after she developed progressive skeletal anomalies with fractures. She presented with multiple wormian bones, acro-osteolysis, severe osteoporosis, bowed fibulae and a renal cyst. Positive genetic test of a de novo heterozygous frameshift mutation in exon 34 of NOTCH2 (c.6426dupT) supported the clinical diagnosis of HCS. CONCLUSION: This is the second reported HCS case caused by the mutation c.6426dupT in NOTCH2, but presenting much earlier and severer clinical expression. Physicians should be aware of variable phenotypes so that early diagnosis and management may be achieved.

Clinical features and mutational analysis in 114 young children with Wilson disease from South China.

Wilson disease (WD) is a rare autosomal recessive disorder caused by mutations in the ATP7B gene. Clinical features and mutational analysis of Chinese children with WD at early age were rarely described. Herein, we retrospectively examined 114 children with WD at the mean of 5.9 years old age at diagnosis. Eight patients developed acute liver failure at mean age of 9.7 years old, 4 of whom died. Among the 114 patients, 86.0% were presymptomatic with isolated elevation of transaminases at diagnosis, 99.1% had decreased ceruloplasmin, and 68.4% had urinary copper excretion over 100 µg/24 hr. Bi-allele pathogenic ATP7B mutations were identified in all patients. Among the 60 mutations detected, 10 were novel, including 7 missense mutations (p.I566N, p.T704I, p.C980F, p.G1030 V, p.A1096Q, p.L1327P, and p.L1373F), 1 nonsense mutation (p.K866X), 1 small insertion (p.Y44LfsX2), and 1 small deletion (p.R1118PfsX10). The most frequent mutations were p.R778L, p.P992L, and p.I1148T, which affected 27.2, 25.4, and 20.2% of the 114 WD children, respectively. The patients carrying p.R778L presented a higher rate of acute liver failure than the patients without p.R778L (9.7% vs. 4.8%). These results will be helpful in establishing early diagnosis of WD at the gene level, offering beneficial information for genetic counseling and providing clues to genotype/phenotype correlation of ATP7B mutations.

Two novel mutations in the ALPL gene of unrelated Chinese children with Hypophosphatasia: case reports and literature review.

OBJECTIVE: Hypophosphatasia (HPP) is an inherited disorder of defective skeletal mineralization caused by mutations in the ALPL gene that encodes the Tissue Non-specific Alkaline Phosphatase (TNSALP). It is subdivided into six forms depending on the age of onset: perinatal lethal, prenatal benign, infantile, childhood, adult, and odonto HPP. Among these, infantile HPP is characterized by early onset and high frequency of lethal outcome. Few studies have reported the phenotype and genetic characteristics of HPP in Chinese children. CASE PRESENTATION: Three forms of HPP were identified in four unrelated patients from four different Chinese families, including one lethal infantile (patient 1), two childhood (patient 2 and 3) and one odonto HPP (patient 4). Six variants in the ALPL gene were identified, including five missense mutations and one frameshift mutation. Of which, none were reported previously in the Chinese population, and two were novel (c.359G > C: p.G120A and c.1017dupG: p.H340AfsX3). Patient 1 carrying a novel homozygous (c.359G > C) mutation showed respiratory distress and pneumonia at first day of his life. He presented nearly negligible level of serum ALP activity, overall skeletal hypominaralization and died at 3 months old. Patient 2, 3 and 4 were compound heterozygotes with decreased serum ALP activity. Patient 2 and 3 presented premature loss of deciduous teeth, muscle weakness and bone pain, whereas patient 4 had early loss of deciduous teeth only. All four pedigrees exhibited autosomal recessive pattern of inheritance. CONCLUSIONS: In this study, six mutations in the ALPL gene were found in four Chinese HPP patients, two of which were novel: c.359G > C in exon 5 and c.1017dupG in exon 10. Our results strongly indicated that the novel mutation c.359G > C might be disease-causing and associated with severe infantile form of HPP.

Clinical and molecular characteristics of patients with Gaucher disease in Southern China.

Gaucher disease (GD) is a common lysosomal storage disorder caused by the deficiency of acid ß-glucosidase, due to mutations in the GBA gene. To explore the clinical and molecular characteristics of GD patients from Southern China, GBA gene were analyzed by nest PCR and direct Sanger-sequencing. Novel missense mutations were transiently transfected in COS-7 cells by plasmid system for functional verification. Among the 22 GD patients, 19 patients were classified as type 1 and three as type 2. Over 60% of the type 1 patient had the onset before two years of age and about 42% of them died before three years of age. Six type 1 patients with L444P homozygous genotype, presented with early onset and severe hepatosplenomegaly. Four novel mutations Y22C, F109L, L149F and c.983_990delCCCACTGG were identified. The GBA activities in vitro of novel mutants Y22C, F109L and L149F were 20.2%, 6.9% and 6.5% of the wild-type, respectively. L444P mutation accounted for 47.7% of the mutant alleles. Our results revealed that type 1 GD tends to present with a severe phenotype among southern Chinese. L444P was the most prevalent mutation and L444P homozygous genotype was associated with severe type 1 GD. Three novel missense mutations identified were pathogenic.

Early prenatal diagnosis of lysosomal storage disorders by enzymatic and molecular analysis.

OBJECTIVE: To report the 4-year experience of early prenatal diagnosis of lysosomal storage disorders (LSDs) at a center in mainland China. METHOD: Forty-seven pregnancies affected with LSDs were assed using enzymes and/or molecular studies. Prenatal studies were performed on 43 uncultured chorionic villi (CV) samples, two amniotic fluid samples, and two umbilical cord blood samples. RESULTS: Of the 47 fetuses, 23 (48.9%) were determined to normal, 13 (27.7%) to be carriers, and 11 (23.4%) diagnosed as affected. In this cohort, mucopolysaccharidoses (MPS) type II was the most common LSD, followed by Pompe disease and then metachromatic leucodystrophy. In the 17 MPS II cases, the four affected fetuses showed MPS II enzyme activity expression levels of 1.4% to 6.7%, while the enzyme activity levels of the 13 normal fetuses ranged from 72% to 240.4%. In the seven Pompe cases, three fetuses were normal with Pompe enzyme activity expression levels of 20%, 38.8%, and 77.3%, while four carrier pregnancies showed enzyme activity levels of 17.5%, 17.5%, 33.4%, and 13.8%, respectively. CONCLUSION: Based on different enzyme properties in uncultured CV, different prenatal diagnostic strategies should be adopted for MPS II and Pompe disease. Combining enzyme assay and molecular studies in uncultured CV improves the reliability of prenatal diagnosis of LSDs.

Clinical and molecular characteristics of 11 Chinese probands with GM1 gangliosidosis.

GM1 gangliosidosis is an autosomal recessive lysosomal storage disease caused by the deficiency of ß-galactosidase activity, precisely due to mutations in the GLB1 gene. To explore the clinical and molecular characteristics of GM1 gangliosidosis patients from China, GLB1 gene were analyzed in 11 probands with GM1 gangliosidosis by exploiting direct Sanger-sequencing. Among them, five patients were classified as the infantile type and the remaining six as the late-infantile or juvenile type. In these probands, eight novel mutations p.Y50N, p.Y237C, p.S267F, p.G453R, p.K578 N, c.618delC, c.475_478delGACA and c.1979_1980insG have been identified. Among them, three novel missense mutations p.Y50N, p.S267F and p.G453R were transiently transfected in COS-7 cells by plasmid system for functional verification. In vitro GLB1 activities carrying the aforesaid missense mutants p.Y50N, p.S267F and p.G453R were 0.11%, 0 and 0.55% of wild-type, respectively. Mutation c.495_497delTCT and p.S149F accounted for 22.7 and 13.6% of the mutant alleles, respectively. Our results expand the spectrum of GLB1 gene, provide new insights into the clinical and molecular characteristics of GM1 gangliosidosis in China.

Brain abnormalities in fucosidosis: transplantation or supportive therapy?

Fucosidosis is a rare lysosomal storage disease caused by α-fucosidase deficiency, which leads to progressive neurological deterioration and death. Hematopoietic stem cell transplantation is the best curative therapy if performed during the early stages of disease. We report two fucosidosis patients with brain abnormalities and the challenge faced in their management. The first patient received supportive therapy and the second one firstly underwent unrelated donor umbilical cord blood transplantation. After a period of follow-up, we found neurological symptoms were worsening day by day on patient1. By contrast, patient2 who received cord blood transplantation acquired clinical neurologic improvement in response to normalization of deficient enzymatic activity. This report indicates that hematopoietic transplant could reduce the severity and retard the progression of clinical neurological deterioration. Umbilical cord blood transplantation is a novel approach for treating fucosidosis patients who lack suitable bone morrow donors.

[Characteristics of DUOXA2 gene mutation in children with congenital hypothyroidism].

OBJECTIVE: To investigate the characteristics of DUOXA2 gene mutation and the genotype-phenotype relationship in children with congenital hypothyroidism (CH) in Guangzhou, China. METHODS: A total of 20 CH patients with suspected thyroid dyshormonogenesis who had no DUOX2 gene mutation were enrolled. These patients who were born between 2011 and 2012 were screened and diagnosed with CH in the Guangzhou Newborn Screening Center. PCR and direct sequencing were used to analyze DUOXA2 gene mutation. RESULTS: Among the 20 patients, 2 had p.Y246X/p.Y246X homozygous mutation; 4 had monoallelic heterozygous mutation, among whom 2 carried the known pathogenic mutation c.413-414insA, 1 carried p.Y246X, and 1 carried a novel mutation, p.G79R. Reevaluation was performed at the age of 2-3 years, and the results showed that the two patients with p.Y246X/p.Y246X homozygous mutation were manifested as transient and mild permanent CH, respectively. Among the four patients with monoallelic heterozygous mutation, the one who carried p.Y246X mutation was manifested as typical permanent CH, and the other three were manifested as transient CH. CONCLUSIONS: DUOXA2 gene mutation is a common molecular pathogenic basis for CH children with suspected thyroid dyshormonogenesis in Guangzhou, and most of them are manifested as transient CH. There is no association between DUOXA2 genotypes and phenotypes. The novel mutation p.G79R is probably a pathogenic mutation.

Clinical,biochemical and molecular analysis of five Chinese patients with Sandhoff disease.

Sandhoff disease (SD) is a rare autosomal recessive lysosomal storage disorder of sphingolipid metabolism resulting from the deficiency of ß-hexosaminidase (HEX). Mutations of the HEXB gene cause Sandhoff disease. In order to improve the diagnosis and expand the knowledge of the disease, we collected and analyzed relevant data of clinical diagnosis, biochemical investigation, and molecular mutational analysis in five Chinese patients with SD. The patients presented with heterogenous symptoms of neurologic deterioration. HEX activity in leukocytes was severely deficient. We identified seven different mutations, including three known mutations: IVS12-26G > A, p.T209I, p.I207V, and four novel mutations: p.P468PfsX62, p.L223P, p.Y463X, p.G549R. We also detected two different heterozygous mutations c.-122delC and c.-126C > T in the promoter which were suspected to be deleterious mutations. We attempted to correlate these mutations with the clinical presentation of the patients. Our study indicates that the mutation p.T209I and p.P468PfsX62 may link to the infantile form of SD. Our study expands the spectrum of genotype of SD in China, provides new insights into the molecular mechanism of SD and helps to the diagnosis and treatment of this disease.

Clinical, biochemical, neuroimaging and molecular findings of X-linked Adrenoleukodystrophy patients in South China.

X-linked adrenoleukodystrophy is a common X-linked recessive peroxisomal disorder caused by the mutations in the ABCD1 gene. In this study, we analyzed 19 male patients and 9 female carriers with X-linked adrenoleukodystrophy in South China. By sequencing the ABCD1 gene, 13 different mutations were identified, including 7 novel mutations, and 6 known mutations, and 1 reported polymorphism. Mutation c.1180delG was demonstrated to be de novo mutation. 26.3 % (5/19) patients carried the deletion c.1415_16delAG, which may be the mutational hot spot in South China population. In addition, 73.7 % (14/19) patients were type of childhood cerebral adrenoleukodystrophy, 26.3 %(5/19) were in Addison only. Half of the childhood cerebral adrenoleukodystrophy patients had the adrenocortical insufficiency preceded the onset of neurological symptoms. Furthermore, 5 of 19 cases underwent hematopoietic stem cell transplantation. Our data showed that hematopoietic stem cell transplantation performed at an advanced stage of the cerebral X- linked adrenoleukodystrophy would accelerate the progression of the disease. Good clinical outcome achieved when hematopoietic stem cell transplantation performed at the very early stage of the disease.

[Kniest dysplasia due to mutation of COL2A1 gene].

OBJECTIVE: To detect potential mutation of COL2A1 gene in two children suspected for Kniest dysplasia. METHODS: The 54 exons and splicing regions of the COL2A1 gene were amplified with PCR and the product was subjected to direct sequencing. RESULTS: A missense mutation (c.905C>T, p.Ala302Val) was found in the coding region of the COL2A1 gene, which has been previously reported in abroad. The patients appeared to have short trunk dwarfism, enlarged joints and midface hypoplasia. CONCLUSION: The probands are the first cases of Kniest dysplasia described in China, and so was the p.Ala302Val mutation.

[Clinical features and StAR gene mutations in children with congenital lipoid adrenal hyperplasia].

This article reported the clinical manifestations, steroid profiles and adrenal ultrasound findings in two unrelated Chinese girls with lipoid congenital adrenal hyperplasia (LCAH). Direct DNA sequencing and restriction fragment length polymorphism (RFLP) analysis were used to identify the mutations of steroidogenic acute regulatory protein (StAR) gene. The two patients with 46,XX karyotype, presented hyperpigmentation, growth retardation, and hyponatremia. Steroid profiles analysis revealed elevated plasma adrenocorticotrophic hormone levels, decreased or normal serum cortisol levels and low levels of androgens. Ultrasound examinations revealed that enlarged adrenals in patient 1 and normal adrenals in patient 2. Direct DNA sequencing of StAR gene showed a reported homozygous for c.772C>T(p.Q258X) in patient 1. Compound heterozygous for c.367G>A(p.E123K) and IVS4+2T>A (both novel mutations) were found in patient 2, inherited from her mother and father respectively. The amino acid of mutant position of the novel p.E123K was highly conserved in ten different species and was predicted to have impacts on the structure and function of StAR protein by the PolyPhen-2 prediction software. RFLP analysis revealed three bands (670, 423 and 247 bp) in patient 2 and her father and two bands (423 and 247 bp) in her mother and 50 controls. It is concluded that LCAH should be considered in girls with early onset of adrenal insufficiency and that steroid profiles, karyotype analysis, adrenal ultrasound and StAR gene analysis may be helpful for the definite diagnosis of LCAH.

[Identification of a novel pathogenic mutation in PDHA1 gene for pyruvate dehydrogenase complex deficiency].

OBJECTIVE: To study the molecular genetic mechanism and genetic diagnosis of pyruvate dehydrogenase complex deficiency (PHD), and to provide a basis for genetic counseling and prenatal genetic diagnosis of PHD. METHODS: Polymerase chain reaction (PCR) was performed to amplify the 11 exons and exon junction of the PDHA1 gene from a child who was diagnosed with PHD based on clinical characteristics and laboratory examination results. The PCR products were sequenced to determine the mutation. An analysis of amino acid conservation and prediction of protein secondary and tertiary structure were performed using bioinformatic approaches to identify the pathogenicity of the novel mutation. RESULTS: One novel duplication mutation, c.1111_1158dup48bp, was found in the exon 11 of the PDHA1 gene of the patient. No c.1111_1158dup48bp mutation was detected in the sequencing results from 50 normal controls. The results of protein secondary and tertiary structure prediction showed that the novel mutation c.1111 _1158dup48bp led to the duplication of 16 amino acids residues, serine371 to phenylalanine386, which induced a substantial change in protein secondary and tertiary structure. The conformational change was not detected in the normal controls. CONCLUSIONS: The novel duplication mutation c.1111_1158dup48bp in the PDHA1 gene is not due to gene polymorphisms but a possible novel pathogenic mutation for PHD.