Characterization of 8 Point Mutations in the Cyp21b Gene in Brazilian Patients With Congenital Adrenal Hyperplasia (Cah) Due To 21-Hydroxylase Deficiency 31

Abstract Background Steroid 21-hydroxylase deficiency is an autosomal recessive disorder, present in 90–95% of all cases with congenital adrenal hyperplasia (CAH). The classical simple virilizing (SV) form of the disease causes virilization of the external genitalia in newborn females and pseudo-precocious puberty in both sexes, due to reactive androgen overproduction. Case presentation We describe a 3.5-year-old girl presenting with pubarche, P2 according to Tanner, advanced bone age of 6 years and 10 months, and high serum levels of 17-hydroxyprogesterone (17-OHP). Molecular analysis of the nine most common pseudogene-derived CYP21A2 point mutations was performed in the patient and her family members using the polymerase chain reaction/amplification-created restriction site (PCR/ACRS) method. We detected the P30L/I172N genotype in the patient. She had inherited a mild P30L mutation from her mother and a severe I172N mutation from her father. Conclusions Although the CAH phenotype is determined by the allele that produces most of the enzyme activity and the mild non-classical (NC) phenotype should be expected, the mild P30L known to be more virilizing probably induced the classical SV phenotype in our patient. A continuous regimen of hydrocortisone at a recommended dose failed to decrease the 17-OHP sufficiently. Careful tapering of the dose did not help, and her pubic hair advanced to P3 according to Tanner. Individually tailored treatment is warranted in this patient.

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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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Molecular Analysis of CYP21A2 Gene Mutations among Iraqi Patients with Congenital Adrenal Hyperplasia

Enzyme Research ◽

10.1155/2016/9040616 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 6

Author(s):

Ruqayah G. Y. Al-Obaidi ◽

Bassam M. S. Al-Musawi ◽

Munib Ahmed K. Al-Zubaidi ◽

Christian Oberkanins ◽

Stefan Németh ◽

...

Keyword(s):

Congenital Adrenal Hyperplasia ◽

Molecular Analysis ◽

Point Mutations ◽

Gene Mutations ◽

Adrenal Hyperplasia ◽

Hydroxylase Deficiency ◽

Cyp21a2 Gene ◽

Gene Deletions ◽

Large Gene ◽

21 Hydroxylase Deficiency

Congenital adrenal hyperplasia is a group of autosomal recessive disorders. The most frequent one is 21-hydroxylase deficiency. Analyzing CYP21A2 gene mutations was so far not reported in Iraq. This work aims to analyze the spectrum and frequency of CYP21A2 mutations among Iraqi CAH patients. Sixty-two children were recruited from the Pediatric Endocrine Consultation Clinic, Children Welfare Teaching Hospital, Baghdad, Iraq, from September 2014 till June 2015. Their ages ranged between one day and 15 years. They presented with salt wasting, simple virilization, or pseudoprecocious puberty. Cytogenetic study was performed for cases with ambiguous genitalia. Molecular analysis of CYP21A2 gene was done using the CAH StripAssay (ViennaLab Diagnostics) for detection of 11 point mutations and >50% of large gene deletions/conversions. Mutations were found in 42 (67.7%) patients; 31 (50%) patients were homozygotes, 9 (14.5%) were heterozygotes, and 2 (3.2%) were compound heterozygotes with 3 mutations, while 20 (32.3%) patients had none of the tested mutations. The most frequently detected mutations were large gene deletions/conversions found in 12 (19.4%) patients, followed by I2Splice and Q318X in 8 (12.9%) patients each, I172N in 5 (8.1%) patients, and V281L in 4 (6.5%) patients. Del 8 bp, P453S, and R483P were each found in one (1.6%) and complex alleles were found in 2 (3.2%). Four point mutations (P30L, Cluster E6, L307 frameshift, and R356W) were not identified in any patient. In conclusion, gene deletions/conversions and 7 point mutations were recorded in varying proportions, the former being the commonest, generally similar to what was reported in regional countries.

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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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Molecular Characterization of Mutations in Indian Children with Congenital Adrenal Hyperplasia due to Steroid 21-Hydroxylase Deficiency

Journal of Pediatric Endocrinology and Metabolism ◽

10.1515/jpem.2001.14.1.27 ◽

2001 ◽

Vol 14 (1) ◽

Cited By ~ 11

Author(s):

R. Mathur ◽

P.S.N. Menon ◽

M. Kabra ◽

R.K. Goyal ◽

I.C. Verma

Keyword(s):

Congenital Adrenal Hyperplasia ◽

Molecular Characterization ◽

Adrenal Hyperplasia ◽

Indian Children ◽

Hydroxylase Deficiency ◽

21 Hydroxylase Deficiency

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Assessment of the most common CYP21A2 point mutations in a cohort of congenital adrenal hyperplasia patients from Egypt

Journal of Pediatric Endocrinology and Metabolism ◽

10.1515/jpem-2019-0575 ◽

2020 ◽

Vol 33 (7) ◽

pp. 893-900

Author(s):

Mona Essawi ◽

Inas Mazen ◽

Lubna Fawaz ◽

Heba Hassan ◽

Nagham ElBagoury ◽

...

Keyword(s):

Congenital Adrenal Hyperplasia ◽

Normal Population ◽

Point Mutations ◽

Common Point ◽

Common Mutation ◽

Adrenal Hyperplasia ◽

Site Mutation ◽

Hydroxylase Deficiency ◽

Egyptian Patients ◽

21 Hydroxylase Deficiency

AbstractObjectivesCongenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) is a common autosomal recessive disorder caused by defects in the CYP21A2 gene. We aimed to determine the prevalence of the most commonly reported mutations among 21-OHD Egyptian patients and correlate genotype with phenotype.MethodsMolecular analysis of the CYP21A2 gene was performed for the detection of the six most common point mutations (p.P30L, p.I172N, p.V281L, p.Q318X, the splice site mutation Int2 [IVS2–13A/C>G], and the cluster of three mutations [p.I236N, p.V237E, and p.M239K] designed as CL6). Polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) method was performed on 47 unrelated Egyptian 21α-OH deficiency patients and their available parents to detect the presence of the six most common point mutations.ResultsScreening for the six most common point mutations in CYP21A2 gene, revealed mutations in 87.2% (82/94) of the studied alleles corresponding to 47 Egyptian patients. The most common mutation among the studied cases was IVS2-13C/A>G that was found to be presented in a frequency of 46.8% (44/94). The genotype/phenotype correlations related to null, A, and B groups were with PPV of 100, 55.5, and 83.3%, respectively.ConclusionsThe described method diagnosed CAH in 80.8% of the studied patients. Good correlation between genotype and phenotype in salt wasting and simple virilizing forms is determined, whereas little concordance is seen in nonclassical one. Furthermore, studying the carrier frequency of 21-OHD among the normal population is of great importance.

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Genotype-Phenotype Correlation in Patients with Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency in Cuba

International Journal of Endocrinology ◽

10.1155/2021/9316284 ◽

2021 ◽

Vol 2021 ◽

pp. 1-6

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 ◽

Clinical Manifestations ◽

Adrenal Hyperplasia ◽

Phenotype Correlation ◽

Hydroxylase Deficiency ◽

Cyp21a2 Gene ◽

Genotype Phenotype Correlation ◽

21 Hydroxylase Deficiency ◽

Cuban Population

Background. There are several studies that show a good genotype-phenotype correlation in congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD). However, there is well-documented evidence of inconsistency in some cases. Objectives. To determine if there is a correlation between the identified mutations and the clinical manifestations of 21OHD in the Cuban population. Methods. A cross-sectional descriptive study of all patients referred for a molecular diagnosis of 21OHD in Cuba from January 2000 to December 2018. The clinical manifestations of each patient were identified and classified according to the phenotype. The CYP21A2 gene was analyzed for the presence of 5 point mutations involved in the pathogenesis of 21OHD (intron 2, deletion of 8bp, I172N, P30L, and Q318X); correlation was sought between the phenotypic characteristics and the frequencies of point mutations in the patients using the Spearman test. Results. A total of 55 patients underwent direct analysis of the CYP21A2 gene in order to determine the presence of the 5 point mutations. Point mutations were identified in 31 patients, which corresponded to 56%. A statistically significant genotype-phenotype correlation was found. Conclusions. The correlation between the detected molecular defect and the clinical expression of 21OHD was reasonable in the Cuban population, which could allow phenotypic predictions to be made from the genotype.

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