Molecular Identification of Intron 2 Splice Mutation and 8bp Deletion in CYP21 Gene for Congenital Adrenal Hyperplasia (CAH) Patients in Kashmir (North India)

Intron 2 Splice Mutation at CYP21 Gene in Patients with Congenital Adrenal Hyperplasia in the Republic of MacedoniaCongenital adrenal hyperplasia (CAH) is an autosomal recessive disorder. In 90-95% of cases it results from mutations in the gene for 21-hydroxylase (CYP21, also termed CYP21A2 and P450c21). The IVS-II-656 (C/A>G) mutation leaves ~2.0% enzyme activity, and comprises 25% of the classic CYP21 deficiency alleles and 51% of alleles in the salt-wasting form.We performed direct molecular diagnosis of the IVS-II mutation in 41 Macedonian patients with different clinical forms of CAH and 55 of their healthy parents and siblings from 37 unrelated families, using the differential polymerase chain reaction/amplification created restriction site method (PCR/ACRS). The IVS-II mutation was detected in 41.5% patients (29.3% were homozygotes and 12.2% were heterozygotes). All homozygotes had a severe classical CAH phenotype (of which 91.7% were salt-wasting and 8.3% were simple virilizing). Three of the heterozygotes had a salt-wasting (SW) phenotype and were compound heterozygotes. The IVS-II mutation was also found in 30.9% of the family members (18.2% were homozygous and 12.7% were heterozygous) and none had any clinical manifestation. The frequency of the IVS-II mutation (41.5%) in these subjects was similar to that reported elsewhere.

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CYP21 GENE MUTATIONS IN SOUTH INDIAN CHILDREN WITH CONGENITAL ADRENAL HYPERPLASIA

10.26226/morressier.57d034d3d462b80292383a9f ◽

2016 ◽

Author(s):

Ganesh RAMASWAMY

Keyword(s):

Congenital Adrenal Hyperplasia ◽

Gene Mutations ◽

Adrenal Hyperplasia ◽

Indian Children ◽

Cyp21 Gene ◽

South Indian

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Molecular diagnosis of patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

BMC Endocrine Disorders ◽

10.1186/s12902-020-00643-z ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Tania Mayvel Espinosa Reyes ◽

Teresa Collazo Mesa ◽

Paulina Arasely Lantigua Cruz ◽

Adriana Agramonte Machado ◽

Emma Domínguez Alonso ◽

...

Keyword(s):

Congenital Adrenal Hyperplasia ◽

Point Mutations ◽

Adrenal Hyperplasia ◽

Hydroxylase Deficiency ◽

Cross Sectional ◽

Salt Wasting ◽

Frequent Mutations ◽

Detection Of Mutations ◽

21 Hydroxylase Deficiency ◽

Intron 2

Abstract Background Congenital adrenal hyperplasia (CAH) is an autosomal recessive group of diseases. 21-Hydroxylase deficiency (21OHD) accounts for between 95 and 99% of all CAH cases. Objectives To characterize the genotype of patients clinically diagnosed with 21OHD and to identify the most frequent mutations in the Cuban population. Methods Cross-sectional descriptive study that included all patients diagnosed with 21OHD from January 2000 to December 2018. For the molecular analysis of the CYP21A2 gene, a protocol was used that used the polymerase chain reaction in 2 stages; in the first stage genomic DNA was amplified and 5 point mutations were detected in the second stage (Intron 2, Deletion of 8 bp, G318X, I172N and P30L). Results The 5 point mutations were identified in 31 of the 55 (56%) studied patients, 16/21 (76%) in the salt-wasting, 12/18 (67%) in the simple virilizing and 3/16 (19%) in the nonclassical form. The Intron 2 mutation was the most frequent, followed by G318X and 8 bp deletion. Compound heterozygotes were found in 10 patients, all corresponded to classic forms of the disease. Conclusions The causal CYP21A2 gene mutation was detected in 56% (72% in classic CAH), which makes the method encouraging. The most frequent mutations observed were Intron 2 and G318X. The detection of mutations offers confirmation of diagnosis, prediction of phenotype and genetic counseling.

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High Variability of CYP21 Gene Rearrangements in Spanish Patients with Classic Form of Congenital Adrenal Hyperplasia

Human Heredity ◽

10.1159/000022804 ◽

1998 ◽

Vol 48 (4) ◽

pp. 216-225 ◽

Cited By ~ 12

Author(s):

M. Natividad Lobato ◽

Rosa Aledo ◽

Anna Meseguer

Keyword(s):

Congenital Adrenal Hyperplasia ◽

High Variability ◽

Gene Rearrangements ◽

Adrenal Hyperplasia ◽

Cyp21 Gene ◽

Classic Form

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Identification of four novel mutations in the CYP21 gene in congenital adrenal hyperplasia in the Chinese

Human Genetics ◽

10.1007/s004390050821 ◽

1998 ◽

Vol 103 (3) ◽

pp. 304-310 ◽

Cited By ~ 36

Author(s):

H.-H. Lee ◽

Hsiang-Tai Chao ◽

Yann-Jinn Lee ◽

San-Ging Shu ◽

Mei-Chyn Chao ◽

...

Keyword(s):

Congenital Adrenal Hyperplasia ◽

Adrenal Hyperplasia ◽

Novel Mutations ◽

Cyp21 Gene

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Identification of three mutatons in the cyp21 gene in Vietnamese patients having signs of congenital adrenal hyperplasia

TAP CHI SINH HOC ◽

10.15625/0866-7160/v35n2.3112 ◽

2013 ◽

Vol 35 (2) ◽

Author(s):

Le Bac Viet ◽

Nguyen Thi Phuong Mai ◽

Nguyen Huy Hoang

Keyword(s):

Congenital Adrenal Hyperplasia ◽

Adrenal Hyperplasia ◽

Cyp21 Gene

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Mutation of IVS2 –12A/C>G in Combination with 707–714delGAGACTAC in the CYP21 Gene Is Caused by Deletion of the C4-CYP21 Repeat Module with Steroid 21-Hydroxylase Deficiency

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2003-030047 ◽

2003 ◽

Vol 88 (6) ◽

pp. 2726-2729 ◽

Cited By ~ 12

Author(s):

Hsien-Hsiung Lee ◽

Shwu-Fen Chang ◽

Fuu-Jen Tsai ◽

Li-Ping Tsai ◽

Ching-Yu Lin

Keyword(s):

Congenital Adrenal Hyperplasia ◽

Donor Site ◽

Adrenal Hyperplasia ◽

Hydroxylase Deficiency ◽

Aberrant Splicing ◽

Cyp21 Gene ◽

Pcr Product ◽

Intergenic Recombination ◽

21 Hydroxylase Deficiency

More than 90% of the cases of congenital adrenal hyperplasia are caused by mutations of the CYP21 gene. Approximately 75% of the defective CYP21 genes are generated through intergenic recombination, termed apparent gene conversion, from the neighboring CYP21P pseudogene. Among them, mutation of the aberrant splicing donor site of IVS2 –12A/C>G at nucleotide (nt) 655 is believed to be a result derived from this mechanism and is the most prevalent case among all ethnic groups. However, mutation of 707–714delGAGACTAC rarely exists alone, although this locus is a distance of 53 nt away from IVS2 –12A/C>G. From the molecular characterization of the mutation of IVS2 –12A/C>G combined with 707–714delGAGACTAC in patients with congenital adrenal hyperplasia, we found that it appeared to be in a 3.2-rather than a 3.7-kb fragment generated by Taq I digestion in a PCR product of the CYP21 gene. Interestingly, the 5′ end region of such a CYP21 haplotype had CYP21P-specific sequences. Our results indicate that the coexistence of these two mutations is caused by deletion of the CYP21P, XA, RP2, and C4B genes and intergenic recombination in the C4-CYP21 repeat module. Surprisingly, this kind of the haplotype of the mutated CYP21 gene has not been reported as a gene deletion.

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Study of a Kindred with Classic Congenital Adrenal Hyperplasia: Diagnostic Challenge due to Phenotypic Variance1

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.83.6.4887 ◽

1998 ◽

Vol 83 (6) ◽

pp. 1940-1945

Author(s):

Daisy Chin ◽

Phyllis W. Speiser ◽

Julianne Imperato-McGinley ◽

Naznin Dixit ◽

Naveen Uli ◽

...

Keyword(s):

Congenital Adrenal Hyperplasia ◽

Newborn Screening ◽

Point Mutation ◽

Phenotypic Expression ◽

Variable Degree ◽

Adrenal Hyperplasia ◽

Cyp21 Gene ◽

Classic Congenital Adrenal Hyperplasia ◽

Genital Ambiguity ◽

21 Hydroxylase Deficiency

We sought to determine the concordance of the phenotype and genotype in a kindred with classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency. The variation in phenotypic expression within this family underscores the difficulty of establishing the diagnosis in the absence of newborn screening, even with a heightened index of suspicion. Steroidogenic profiles were obtained for the three affected siblings. The available clinical history of the two affected aunts was retrieved. Genotyping was performed on several members of the kindred. Detailed sequencing of the entire CYP21 gene of two clinically dissimilar subjects in this family was undertaken to explore the possibility of other mutations or polymorphisms. PCR with ligase detection reaction analysis of CYP21 revealed that the affected family members III-2, III-3, III-4, II-3, and II-4, all were compound heterozygotes carrying the intron 2 point mutation known to interfere with splicing (nucleotide 656 A to G) and the exon 4 point mutation causing a nonconservative substitution of asparagine for isoleucine at codon 172 (I172N). Detailed sequencing of the gene was performed for the two most phenotypically dissimilar subjects. A single silent polymorphism was found in the third nucleotide for codon 248 in patient II-4, but not in patient III-4, and no additional mutations were found. Classic congenital adrenal hyperplasia remains a difficult diagnosis to make in the absence of newborn screening because of the variability of phenotypic expression. Likewise, the variable degree of genital ambiguity in affected females in this family serves to question universal advocacy of prenatal steroid treatment in pregnancies at risk for congenital adrenal hyperplasia. Extensive molecular exploration did not provide an explanation of the phenotypic heterogeneity and supports the possibility of influences other than the CYP21 gene for the observed divergence.

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