Spectacular advances in molecular genetics have enabled the molecular characterisation of many genetic disorders. The clinical applications include: (i) identification of pre-symptomatic and symptomatic affected individuals (monogenic diseases), allowing for early treatment and prevention of complications, (ii) carrier testing for genetic counselling, (iii) pharmacogenetic testing to guide medical treatment, and (iv) susceptibility testing (in polygenic diseases) to determine the risk of developing future disease. Using the model of congenital adrenal hyperplasia (CAH), direct mutational analysis can be applied to: (i) confirm the diagnosis when hormone assays have been equivocal, which would allow for early treatment and prevention of adrenal crisis, (ii) prenatal diagnosis and prenatal treatment in affected females to prevent or reduce prenatal virilisation, (iii) heterozygote carrier identification for genetic counselling, (iv) novel therapeutic applications to optimise treatment, including adjusting the steroid dose based on consistent genotype-phenotype correlations, so as to reduce the incidence of growth-inhibiting effects of steroid excess. However, molecular analysis can occasionally be complicated by multiple mutations on one allele, which may potentially affect genotype-phenotype correlations. Hence, molecular genetic analysis of CAH may eventually be adopted as a second tier confirmation of the disease, but is unlikely to replace the current first tier screening assays of precursor steroid metabolites proximal to the enzyme deficiency.
Adrenal Hyperplasia, Congenital ; diagnosis ; genetics ; Humans ; Molecular Diagnostic Techniques

OBJECTIVETo assess the frequencies of CYP21A2 gene mutations among patients from Fujian area with classical 21-hydroxylase deficiency.

METHODSFor 19 probands from different families affected with classical steroid 21-hydroxylase deficiency and 74 family members, mutations of the CYP21A2 gene were analyzed with combined nested polymerase chain reaction, Sanger sequencing and multiplex ligation-dependent probe amplification. Time resolved fluorescence immunoassay was performed to determine the level of 17-hydroxyprogesterone (17-OHP) in all family members. Clinical data and laboratory results of the probands and their family members were analyzed.

RESULTSEleven mutations were identified among the 38 alleles from the 19 probands. 92.1% (35/38) of the mutant CYP21A2 alleles were due to recombination between CYP21A2 and CYP21A1P. Gene conversion and deletions were identified in 84.2% (32/38) and 7.9% (3/38) of the alleles, respectively. IVS2-13A/C>G and chimeras were the most common mutations, which respectively accounted for 34.2% (13/38) and 18.4% (7/38) of all mutant alleles. Among these, IVS2+1G>A and Q318X+356W were first reported in China. 74.3% (55/74) of the family members were carriers of heterozygous mutations. However, no significant difference was found in the 17-OHP levels between carriers and non-carriers (P>0.05).

CONCLUSIONThere seems to be a specific spectrum of CYP21A2 gene mutations in Fujian area, where IVS2-13A/C>G and chimeras are the most common mutations.

Adrenal Hyperplasia, Congenital ; genetics ; Alleles ; Female ; Humans ; Male ; Mutation ; genetics ; Steroid 21-Hydroxylase ; genetics

OBJECTIVE: To explore the genotype-phenotype correlation among 18 patients with 21-hydroxylase deficiency (21-OHD). METHODS: PCR-Sanger sequencing was used to analyze the 10 exons and flanking regions of the CYP21A2 gene among the 18 patients and 20 healthy controls. RESULTS: Seventeen patients had variants of the CYP21A2 gene. Eight patients (44.4%, 8/18) carried homozygous variants including p.Ile 173Asn (62.5%, 5/8), p.Pro31Leu (25.0%, 2/8), and IVS2-13A/C>G (12.5%, 1/8), respectively. Six patients (33.3%, 6/18) carried compound heterozygous variant, among which IVS2-13 A>G+p.Ile 173Asn were most common (50.0%). 94.4% (34/36) of the variant were pathogenic, with the most common variants being p.Ile173Asn (41.7%), IVS2-13A/C>G (19.4%), and p.Ile173Asn (7.5%). No variant was identified among the 20 healthy controls. CONCLUSION The majority of 21-OHD patients carried CYP21A2 gene variants in homozygous or compound heterozygous forms, among which the p.Ile173Asn was the most common one. There is a strong correlation between the genotypes and clinical phenotypes.
Adrenal Hyperplasia, Congenital ; genetics ; Genotype ; Humans ; Mutation ; Phenotype ; Steroid 21-Hydroxylase ; genetics

OBJECTIVE: To identify pathogenic variants in 5 sporadic patients and two Chinese pedigrees affected with 17-hydroxylase deficiency (17-OHD). METHODS: Peripheral blood samples were collected with informed consent. Variants of CYP17A1 gene were screened by PCR and Sanger sequencing. Suspected mutations were validated in other members of the pedigrees. RESULTS: Gene sequencing has identified a homozygous c.985_987delTACinsAA (Y329Kfs) mutation in exon 6 of the CYP17A1 gene in 4 patients and the sister of case 3. Case 1 was found to harbor compound heterozygous mutations c.1459_1467del9 (p.D487_F489del) and c.1244-3C>A. The parents and brother of cases 2 and 5 were heterozygous carriers of a c.985_987delTACinsAA(Y329Kfs) mutation. CONCLUSION Mutations of the CYP17A1 gene probably underlie the pathogenesis of 17-OHD, for which c.985_987delTACinsAA(Y329Kfs) is the most common. The c.1244-3C>A is a novel mutation. Above results have facilitated genetic counseling for the affected families.
Adrenal Hyperplasia, Congenital ; genetics ; Exons ; Female ; Humans ; Male ; Mutation ; Pedigree ; Steroid 17-alpha-Hydroxylase ; genetics

21 hydroxylase deficiency (21-OHD), the most common form of congenital adrenal hyperplasia, is caused by defects in CYP21A2 gene, which encodes the cytochrome P450 oxidase (P450C21) involved in glucocorticoid and mineralocorticoid synthesis. The diagnosis of 21-OHD is based on the comprehensive evaluation of clinical manifestation, biochemical alteration and molecular genetics results. Due to the complex structure of CYP21A2, special techniques are required to perform delicate analysis to avoid the interference of its pseudogene. Recently, the state-of-the-art diagnostic methods were applied to the clinic gradually, including the steroid hormone profiling and third generation sequencing. To standardize the laboratory diagnosis of 21-OHD, this consensus was drafted on the basis of the extensive knowledge, the updated progress and the published consensuses and guidelines worldwide by expert discussion organized by Rare Diseases Group of Pediatric Branch of Chinese Medical Association, Medical Genetics Branch of Chinese Medical Doctor Association, Birth Defect Prevention and Molecular Genetics Branch of China Maternal and Child Health Association. and Molecular Diagnosis Branch of Shanghai Medical Association.
Child ; Humans ; Adrenal Hyperplasia, Congenital/genetics* ; Steroid 21-Hydroxylase/genetics* ; Consensus ; China ; Clinical Laboratory Techniques ; Mutation

OBJECTIVE: Genetic screening and prenatal diagnosis was performed in eighteen families with high risk of 21-hydroxylase deficiency (21-OHD) to provide valuable information for genetic counseling in these affected families. METHODS: First, multiplex ligation-dependent probe amplification (MLPA) combined with nested-PCR based Sanger sequencing was used to detect CYP21A2 gene mutations in probands and their parents of eighteen families, with seven probands had been dead. Second, paternity test was applied to exclude the possibility of maternal genomic DNA contamination, and fetal prenatal diagnosis is based on the mutations found in proband or parents of the family. RESULTS: Ten mutations were identified in these eighteen families, including large fragment deletion, I2G, E3del8bp, I172N, V281L, E6 cluster, L307Ffs, Q318X, R356W and R484Pfs. All probands were caused by homozygous or compound heterozygous mutations of CYP21A2 gene and their parents were carriers. By comparing short tandem repeat sites contamination of maternal genomic DNA was not found in fetal DNA. Prenatal diagnosis showed that five fetus were 21-OHD patients, four fetus were carriers and the other nine fetus were normal. CONCLUSION CYP21A2 gene mutation is the etiology of 21-OHD. Genetic testing of CYP21A2 could assist physicians in 21-OHD diagnosis and provided genetic counseling and prenatal diagnosis for parents who are at risk for having a child with congenital adrenal hyperplasia.
Adrenal Hyperplasia, Congenital ; diagnosis ; genetics ; Female ; Genetic Testing ; Humans ; Mutation ; Pregnancy ; Prenatal Diagnosis ; Steroid 21-Hydroxylase

Objective: To analyze the clinical and genetic characteristics of 33 children with congenital lipoid adrenal hyperplasia (CLAH) caused by StAR gene defects. Methods: The clinical, biochemical, genetic, and follow-up (until December 2021) data of 33 children diagnosed with CLAH from 2006 to 2021 were retrospectively analyzed in Xinhua Hospital, Shanghai Jiao Tong University School of Medicine. Results: Of the 33 children with CLAH, 17 had a karyotype of 46, XX and 16 had a karyotype of 46, XY; 31 were female and 2 were male by social gender. Classic type and non-classic type were found in 30 and 3 children respectively. The age at diagnosis was 9.0 (3.0, 34.5) months. All the 30 cases with classic CLAH presented within the first year of life with skin hyperpigmentation (28 cases, 93%), vomiting and(or) diarrhea (19 cases, 63%), no increase in body weight (8 cases, 27%), elevated adrenocorticotropic hormone levels (21cases (70%)>275 pmol/L), decreased cortisol levels (47 (31,126) nmol/L), hyponatremia ((126±13) mmol/L), hyperkalemia ((5.7±1.1) mmol/L), and normal 17α-hydroxyprogesterone levels (30 cases, 100%). All these with classic CLAH exhibited female external genitalia. Three children with non-classic CLAH (including 2 cases of 46, XY and 1 case of 46, XX) also showed signs and symptoms of adrenal insufficiency, but 2 of them had an age of onset later than 1 year of age, including 1 case of 46, XY with male external genitalia and 1 case of 46, XX with female external genitalia. The other 46, XY patient with non-classic CLAH presented with adrenal insufficiency at 2 months of age, showing micropenis and hypospadias. In the 17 females with 46, XX, 4 older than 10 years of age showed spontaneous pubertal development. A total of 25 StAR gene pathogenic variants were identified in 33 patients, with p.Q258* (18/66, 27%), p.K236Tfs*47 (8/66, 12%) and p.Q77* (6/66, 9%) being the common variantion. Six novel variants were found, including c.358T>G, c.713_714del, c.125del, c.745-1G>A, c.179-2A>C, and exon 1 deletion. Conclusions: Patients with classic CLAH typically present with signs and symptoms of primary adrenal insufficiency in the early infancy period and female external genitalia. p.Q258*, p.K236Tfs*47 and p.Q77* are common variants in CLAH patients.
Adrenal Hyperplasia, Congenital/genetics* ; Adrenal Insufficiency ; Adrenocorticotropic Hormone ; Child, Preschool ; China ; Disorder of Sex Development, 46,XY ; Female ; Humans ; Hydrocortisone ; Hydroxyprogesterones ; Hyperplasia ; Infant ; Male ; Mutation ; Phosphoproteins/genetics* ; Retrospective Studies

OBJECTIVETo discuss the genetic diagnosis of congenital adrenal hyperplasia (CAH) and investigate the resource of gene mutations in CAH.

METHODEnzymatic methods with restriction endonucleases that specifically recognized the mutation sites were used to detect the gene mutations in patients with CAH and their relatives. Polymerase chain reaction and direct sequencing were used to identify the mutations in 21-hydroxylase gene, and short tandem repeat (STR) typing was used to determine the sources of the mutations.

RESULTSOne CAH patient had two known mutations in 21-hydroxylase gene, namely the I2g and I172N mutations. The former mutation was inherited from the biological mother and the latter was not inherited.

CONCLUSIONThe 9 common mutations of CAH are also the hotspots for new mutations.

Adrenal Hyperplasia, Congenital ; diagnosis ; genetics ; Gene Deletion ; Genotype ; Humans ; Mutation ; Point Mutation ; Polymerase Chain Reaction ; Steroid 21-Hydroxylase ; genetics

CYP21A2 gene mutations in a child with congenital adrenal hyperplasia (CAH), and the child's parents, were detected in the study. The clinical features, treatment monitoring and molecular genetic mechanism of CAH are reviewed. In the study, DNA was extracted from peripheral blood samples using the QIAGEN Blood DNA Mini Kit; a highly specific PCR primer for CYP21A2 gene was designed according to the sequence difference between CYP2lA2 gene and its pseudogene; the whole CYP2lA2 gene was amplified with PrimeSTAR DNA polymerase (Takara), and the amplification product was directly sequenced to detect and analyze CYP2lA2 gene mutation. The child was clinically diagnosed with CAH (21-hydroxylase deficiency, 21-OHD) at the age of 36 days, and the case was confirmed by genetic diagnosis at the age of 1.5 years. The proband had a homozygous mutation at c.293-13C in the second intron of CYP21 gene, while the parents had heterozygous mutations. Early diagnosis and standard treatment of CAH (21-OHD) should be performed to prevent salt-wasting crisis and reduce mortality; bone aging should be avoided to increase final adult height (FAH), and reproductive dysfunction due to oligospermia in adulthood should be avoided. These factors are helpful for improving prognosis and increasing FAH. Investigating the molecular genetic mechanism of CAH can improve recognition and optimize diagnosis of this disease. In addition, carrier diagnosis and genetic counseling for the proband family are of great significance.
17-alpha-Hydroxyprogesterone ; blood ; Adrenal Hyperplasia, Congenital ; blood ; genetics ; Humans ; Infant ; Male ; Mutation ; Steroid 21-Hydroxylase ; genetics

OBJECTIVETo investigate gene mutations and the relationship between genotypes and clinical phenotypes in Uygur children with 21-hydroxylase deficiency (21-OHD) in Xinjiang, China.

METHODSA total of 20 Uygur children with 21-OHD who visited the hospital between October 2013 and October 2014 were enrolled. Full-length direct sequencing and multiplex ligation-dependent probe amplification (MLPA) were used to detect the mutations of CYP21A2 gene, which encoded 21-hydroxylase. According to the type of mutation, the patients with 21-OHD were divided into different groups to analyze the consistency between predicted clinical phenotypes and actual clinical phenotypes.

RESULTSA total of 9 mutation types were found in the 20 patients, and 8 of them were identified as pathogenic mutations, i.e., Del, conv, I2g, I172N, Cluster E6, 8-bp del, V281L, and R356W. The other mutation is the new mutation occurring in intron 5 (c.648+37A>G), which had not been reported, and its pathological significance remains unknown. Most clinical phenotypes predicted by mutation types had a higher coincidence rate with actual clinical phenotypes (above 67%), and the clinical phenotypes predicted by P30L and V281L had a lower coincidence rate with actual clinical phenotypes (below 33%).

CONCLUSIONSThe genotype of 21-OHD has a good correlation with phenotype, and the clinical phenotype can be predicted by detecting the patient′s genotype. The new mutation (c.648+37A>G) may be related to the pathogenesis of 21-OHD.

Adolescent ; Adrenal Hyperplasia, Congenital ; enzymology ; ethnology ; genetics ; Child ; China ; ethnology ; Female ; Genotype ; Humans ; Male ; Mutation ; Phenotype ; Steroid 21-Hydroxylase ; genetics