Identification of frequency and distribution of the nine most frequent mutations among patients with 21-hydroxylase deficiency in Turkey

Coexistence of Ovarian Granulose Cell Tumor, Congenital Adrenal Hyperplasia, and Triple Translocation: Is a Consequence or Coincidence?

PURPOSE

Congenital adrenal hyperplasia (CAH) is rare autosomal recessive disease. CAH due to 21-hydroxylase deficiency accounts for 95% of cases. We aimed to share the first case of coexistence of simple virilizing-type congenital adrenal hyperplasia [I172N mutation in the CYP21A], triple translocation [t(9;11;12)], and ovarian granulose cell tumor.

METHODS

A 59-year-old female patient was presented to our clinic, complaining with abdominal pain and distension. Physical examination revealed palpable abdominal mass, virilism, ambiguous genitalia, clitoramegaly, and hyperpigmentation. Contrast-enhanced abdominal computed tomography showed a giant mass originating from the right tubo-ovarian structure.

RESULTS

The patient was operated in the light of the clinico-radiological features mentioned above. A giant mass weighing 3500 g was detected on the right tubo-ovarian structure during laparotomy, and mass was excised with right tubo-ovarian structure. Immunohistochemical examination revealed ovarian granulosa cell tumor. The high serum concentration of 17-OH progesterone was measured at baseline and after 250-μg bolus of synthetic ACTH. In genetic analysis, we screened for six-point mutations, large deletions, and non-common mutations using restriction fragment length polymorphism (RFLP) methods, PCR, and sequencing of CYP21 gene respectively. The patient was detected to be homozygous for the I172N mutation. In addition, 50% of the metaphases examined had triple translocation [t(9;11;12)].

CONCLUSION

The coexistence of congenital adrenal hyperplasia, triple chromosomal translocations, and ovarian granulosa cell tumor has not been described previously. This coexistence may be a sign of a new syndrome.

Comprehensive Genetic Testing of CYP21A2: A Retrospective Analysis in Patients with Suspected Congenital Adrenal Hyperplasia

The most common form of congenital adrenal hyperplasia (CAH) results from a deficiency of the 21-hydroxylase enzyme (21-OHD), presenting with a broad spectrum of clinical phenotypes according to the CYP21A2 gene mutations. Of the 59 patients with suspected CAH, 62.7% presented a positive genetic result. Of them, 78.4% and 18.9% presented with non-classical and classical forms, respectively. An overall phenotype-genotype correlation of 88.9% was observed. Biochemically, 17-hydroxiprogesterone concentrations were significantly higher in genetically confirmed patients. Genetically, 36 patients presented with previously reported pathogenic variants, and one presented a new variant in homozygosis. Among the 74 alleles tested, point mutations were found in 89.2% and large rearrangements were found in the rest. The most prevalent pathogenic variant was p.(Val282Leu). The inclusion of relatives revealed one further case. Interestingly, 87.5% of relatives were carriers of a pathogenic variant, including two siblings initially classified as genetically positive. In addition, the study of male partners with gestational desire identified several carriers of mild mutations. Studying the allelic distribution of the variants also allowed for reclassifying one patient. In conclusion, a genetic approach including Sanger sequencing, multiplex ligation-dependent probe amplification (MLPA) analysis, and allelic distribution of the pathogenic variants represents a beneficial tool for better classifying patients with 21-OHD.

A Case of Salt-Wasting Congenital Adrenal Hyperplasia with Triple Homozygous Mutation: Review of Literature

Congenital adrenal hyperplasia (CAH) due to steroid 21-hydroxylase deficiency represents a group of autosomal recessive disorders characterized by impaired cortisol production due to altered upstream steroid conversions, subclassified as classic and nonclassic forms. The genotype-phenotype correlation is possible in the most frequent case but not in all. Despite in literature many mutations are known, there is the possibility of finding a new genetic pattern in patients with CAH.

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

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.

The spectrum of CYP21A2 mutations in Congenital Adrenal Hyperplasia in an Indian cohort

Congenital Adrenal Hyperplasia (CAH) is a common autosomal recessive disorder of the adrenal steroidogenic pathway. The most common form of CAH is due to mutations in CYP21A2 gene. The incidence of mutations in the CYP21A2 gene and the genotype-phenotype correlations vary among different populations. Therefore, the aim of the study was to establish the spectrum of mutations and to evaluate genotype-phenotype correlation in Indian CAH population. Molecular defects were investigated in 110 alleles (55 patients) in the present study. Notably, we identified disease causing mutations in 106 of 110 (96.4%) alleles whereas the frequency of undetectable mutations was 3.6%. The i2g mutation (20%) was found to be the most common in CAH patients. The second most common mutation was p.R356W (14.5%). p.I172N and 8-bp deletion in exon 3 accounted for 12.7% of the mutated alleles. In descending order, the other mutations present were p.Q318X (9%), E6 Cluster (5.4%), p.V281L (3.6%) and large gene deletion (3.6%). Additionally, p.P267L and frameshift mutation (L307fs/F306+T) were also detected in the Indian cohort with frequency of 1.8% and 5.4% respectively.rare mutation/rare mutations in the CYP21A2 gene were detected viz., p.D234D (NCBI accession number - KF812549), p.F306V (NCBI accession number - KF534754), p.P357P (NCBI accession number - KF692099) and p.H365N (NCBI accession number - KF447378). The genotypes of the patients were categorized into four groups null, A, B and C. Of note, correlation between genotype and phenotype is sufficiently strong, to be of clinical significance in the genetic counseling.

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

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.

Clinical review of 95 patients with 46,XX disorders of sex development based on the new Chicago classification

STUDY OBJECTIVE

The aim of our study was to determine the etiologic distribution of 46,XX disorder of sexual development (DSD) according to the new DSD classification system and to evaluate the clinical features of this DSD subgroup in our patient cohort.

PARTICIPANTS

The evaluation criteria and clinical findings of 95 46,XX patients were described by clinical presentation, gonadal morphology, genital anatomy, associated dysmorphic features, presence during prenatal period with/without postnatal virilization, hormonal characteristics, and presence or absence of steroidogenic defects among 319 patients with DSD.

RESULTS

Types and ratios of each presentation of our 95 patients with 46,XX DSD were as follows: 82 had androgen excess (86.3%): (74 had classical congenital adrenal hyperplasia, 2 had CAH variant possibility of P450-oxidoreductase gene defect), 6 had disorders of ovarian development (6.3%): (1 patient had gonadal dysgenesis with virilization at birth with bilateral streak gonad, 4 patients had complete gonadal dysgenesis, and 1 patient had ovotesticular DSD) and 7 had other 46,XX DSD. Two sisters, who had 46,XX complete gonadal dysgenesis,were diagnosed with Perrault Syndrome with ovarian failure due to streak gonads and associated with sensorineural deafness.

CONCLUSION

46,XX DSD are usually derived from intrauterine virilization and CAH is the most common cause of 46,XX DSD due to fetal androgen exposure.

Prevalence and long-term follow-up outcomes of testicular adrenal rest tumours in children and adolescent males with congenital adrenal hyperplasia

OBJECTIVE

There are a few studies regarding the prevalence of testicular adrenal rest tumours (TARTs) in boys and adolescent males with congenital adrenal hyperplasia (CAH), and there is little information regarding the treatment outcomes in patients with TARTs. The aim of this study was to determine the long-term treatment outcomes in boys and adolescent males with CAH.

PATIENTS AND METHODS

Sixty boys and adolescent males with CAH, who were between 2 and 18 years of age, were included in the study. Fifty-five patients had 21-hydroxylase deficiency (21-OHD), and five patients had 11-β hydroxylase deficiency (11β-OHD). All patients were screened for TARTs by scrotal ultrasonography (US) performed by an experienced radiologist.

RESULTS

TART prevalence was 18·3% in 2-18 years' of age; eight patients had 21-OHD, and three had 11β-OHD. The youngest patient with TART was 4 years old, whereas eight patients with RTs were at puberty. Only two patients had tight metabolic control: eight patients had stage 2, one had stage 4, and two had stage five rest tumours. In four patients with stage 2 TARTs, tumours disappeared after high-dose steroid treatment and did not recur. Shrinkage of tumour was observed in two patients. Testis-sparing surgery was performed in one patient with stage five tumour. Gonadal functions were normal in patients with partially regressed tumours. Two patients became fathers of healthy male off-springs.

CONCLUSIONS

Detection and treatment for TARTs in children with CAH at younger ages, earlier stages, may prevent infertility in adulthood. Therefore, we recommend that scrotal US screening should be performed in every 1-2 years starting from early childhood.

A giant ovarian cyst in a neonate with classical 21-hydroxylase deficiency with very high testosterone levels demonstrating a high-dose hook effect

Congenital adrenal hyperplasia (CAH) is a group of disorders affecting the adrenal steroid synthesis. The most common form, 21-hydroxylase deficiency (21-OHD), leads to decreased production of cortisol and aldosterone with increased androgen secretion. In classic CAH, glucocorticoid treatment can be life-saving and serves to bring the symptoms under control. However, the treatment challenge is to effectively control the excess androgen effect by using the lowest possible glucocorticoid dose. Previous studies suggested a relationship between ovarian cyst formation and adrenal androgen excess, but neonatal large ovarian cysts have been very rarely reported in newborns with CAH. Here, we present the unique case of a neonate with classical 21-OHD who underwent surgery for a giant (10x8x7 cm) unilateral solitary ovarian follicular cyst on the 2nd postnatal day. Hormonal evaluation of the patient revealed high-dose hook effect for serum testosterone levels for the first time by a two-site immunoradiometric assay. Possible mechanisms by which androgen excess may cause ovarian cyst formation are discussed.

Steroid 21-hydroxylase gene mutational spectrum in 50 Tunisian patients: characterization of three novel polymorphisms

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disease of steroid biosynthesis in humans. More than 90% of all CAH cases are caused by mutations of the 21-hydroxylase gene (CYP21A2), and approximately 75% of the defective CYP21A2 genes are generated through an intergenic recombination with the neighboring CYP21A1P pseudogene. In this study, the CYP21A2 gene was genotyped in 50 patients in Tunisia with the clinical diagnosis of 21-hydroxylase deficiency. CYP21A2 mutations were identified in 87% of the alleles. The most common point mutation in our population was the pseudogene specific variant p.Q318X (26%). Three novel single nucleotide polymorphism (SNP) loci were identified in the CYP21A2 gene which seems to be specific for the Tunisian population. The overall concordance between genotype and phenotype was 98%. With this study the molecular basis of CAH has been characterized, providing useful results for clinicians in terms of prediction of disease severity, genetic and prenatal counseling.

Molecular characterization of 25 Chinese pedigrees with 21-hydroxylase deficiency

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders mainly caused by a defect in the steroid 21-hydroxylase gene (CYP21A2). In this study, we investigated the molecular defects of 25 Chinese pedigrees with 21-hydroxylase deficiency (21-OHD). Diagnosis of the probands in the families was based on their typical clinical presentations, such as inborn ambiguous genitalia, or early onset of salt wasting and biochemical metabolite abnormalities. All 10 exons and exon-intron boundaries of the CYP21A2 gene were amplified from the genomic DNA of the probands and then analyzed by direct sequencing. The phenotypes of the 26 patients from 25 pedigrees were classified as the classical form of 21-OHD. One novel mutation (c.1223 G>T) and 13 recurrent mutations of CYP21A2 were identified in the 25 pedigrees by genetic analysis. The novel c.1223 G>T mutation results in the substitution of arginine by leucine at amino acid position 408 (p.Arg408Leu). The most frequent mutation alleles were IVS2-13A/C>G (14/52) and I172N (11/52), followed by chimeric mutations (10/52). Forty six of 52 mutated alleles resulted from pseudogene conversion and 6 of 52 from random mutations. The spectrum of CYP21A2 mutation in our study was slightly different from those previously reported in Chinese and in other ethnic groups of the world. Although microconversion events were the main cause of mutations in the CYP21 gene, random mutations with a common origin can also be the reason for 21-OHD.

Characteristics and prevalence of non-classical congenital adrenal hyperplasia with a V2811 mutation in patients with premature pubarche

We aimed to determine the prevalence and clinical characteristics of non-classical congenital adrenal hyperplasia (NCCAH) with V281L mutation in patients with premature pubarche. An adrenocorticotrophic hormone (ACTH) stimulation test was performed in 14 of the 159 patients with premature pubarche (PP). Patients whose stimulated 17alpha-hydroxyprogesterone (17-OHP) level on the ACTH test was > or =10 ng/mL underwent a mutational analysis of the CYP21 gene. NCCAH was defined in nine (5.7%) patients, all of whom had the V281L mutation. Four of the NCCAH patients were homozygote and four of them were heterozygote. One other patient was compound heterozygote for V281L mutation and the I2 splice mutation. One of the patients with V281L heterozygous mutation developed true precocious puberty and the other one had rapid progressive early puberty and developed polycystic ovary syndrome. ACTH stimulated 17-OHP > or = 10 ng/mL in PP patients is load star to mutation analysis and heterozygote patients should be followed for clinical and biological hyperandrogenism up to completion of the whole 'genome sequence'.

CYP21A2 gene mutations in congenital adrenal hyperplasia: genotype-phenotype correlation in Turkish children

BACKGROUND

Congenital adrenal hyperplasia (CAH) due 21-hydroxylase deficiency (21-OHD) is a common autosomal recessive disorder. It is caused by defects in the CYP21A2 gene.

OBJECTIVE

Our aim was to determine the frequency of common gene mutations and to evaluate genotype-phenotype correlations in Turkish 21-OHD patients.

METHODS

Molecular analysis of the CYP21A2 gene was performed for the detection of the eight most common point mutations [p.P30L, IVS2-13C>G (IVS-2), p.I172N, exon 6 mutation cluster (p.I236N, p.V237E, p.M239K), p.V281L, p.Q318X, p.R356W, 8-bp-deletion], of large deletion and conversion by southern blotting, allele specific semi-quantitative PCR/enzyme restriction method and sequencing, in 56 patients with 21-OHD, from 52 families.

RESULTS

Disease-causing mutations were identified in 77 out of 91 alleles (84.6%) of the patients. Mutations were found in 34 of 43 alleles (79.1%) in salt wasting (SW; n=26), 32 of 36 alleles (88.8%) in simple virilizing (SV; n=24) and 11 of 12 alleles (91.6%) in non-classical (NC; n=6) form of CAH. The most frequent mutations were IVS-2 (22.0%), large conversion (14.3%), p.I172N (9.9%) p.R356W (8.8%), and large deletion (6.6%). In the SW form, the most frequent genotypes were homozygous for IVS-2 (11.5%) and homozygous for large conversion of the gene (11.5%). In the SV form, the most frequent genotype was homozygous for IVS-2 (20%), followed by compound heterozygous for p.I172N/8-bp del (10%). Homozygous for p.V281L (16.7%) was most common in NC. In most cases there was good correlation between genotype and phenotype. In the SW and NC forms, genotypes of all the patients correlated with their phenotypes.

CONCLUSIONS

This is the first comprehensive study on the molecular basis of CAH patients in the Turkish population. Based on these results, we propose a modified screening strategy to facilitate molecular testing of CAH patients in our population.