Non‐classical 21‐hydroxylase deficiency in children: association of adrenocorticotropic hormone‐stimulated 17‐hydroxyprogesterone with the risk of compound heterozygosity with severe mutations

Abstract

Aim: To investigate the association between levels of 17‐hydroxyprogesterone (17‐OHP) and the risk of being compound heterozygous for severe mutations in children with non‐classical 21‐hydroxylase deficiency (NC21OHD). Methods: In 86 Spanish NC21OHD children (75 families) an analysis of the 21‐hydroxylase (21‐OH) gene was performed by CYP21B‐specific polymerase chain reaction amplification, allele‐specific oligonucleotide hybridization and Southern blotting. Familial analysis established how the alleles segregated, and allowed the selection of 21‐OH‐genotyped normal and carrier children, which proved useful in determining a more precise definition of the cut‐off for diagnosis. Receiver operating characteristics (ROC) curve analyses were performed to determine the potential value of 17‐OHP in predicting compound heterozygosity for severe mutations. Results: Thirty‐four of the 86 children (39%) were found to carry one severe 21‐OH mutation (7.3% deletions or conversions, 2.7% 655G, 2.7% Q318X, 1.3% I172N, 1.3% R356W, and 3.3% double microconversions or small conversions involving single exons). The predominant mutation was V281L (56.7%). P453S and P30L were less frequent (3.3 and 2%). No patient showed two severe mutations. The degree of enzymic deficiency, as measured by basal or adrenocorticotropic hormone (ACTH)‐stimulated 17‐OHP levels in fully genotyped patients, but not clinical severity (age and number of symptoms at diagnosis), was found to be significantly greater in children with the severe/mild genotype. ROC curve analyses revealed a strong association between ACTH‐17‐OHP and genotype (area under the curve 0.908, SE 0.057). Conclusion: ACTH‐stimulated 17‐OHP may predict the risk of severe mutations in compound heterozygosity in children (maximum predictive value 93% sensitivity and 83% specificity for a cut‐off at 151 nmol 1‐1), although a certain overlap in individual values is observed and performance of molecular analysis should never be obviated in the genetic counselling of these patients.

<b><i>CYP21A2</i></b> Gene Pathogenic Variants: A Multicenter Study on Genotype–Phenotype Correlation from a Portuguese Pediatric Cohort

“…Moreover, as previously reported, NC 21OHD patients that are compound heterozygotes for a severe pathogenic variant present higher levels of ACTH-stimulated 17OHP than homozygotes/compound heterozygotes for milder alleles [34]. …”

Relationship of CYP21A2 genotype and serum 17-hydroxyprogesterone and cortisol levels in a large cohort of Italian children with premature pubarche

“…Homozygosity for mild mutations was found in 52.7% of our patients, a percentage strikingly higher than that recently reported in a large series of French adult patients (26) and in previous studies in adult Brazilian patients (23), but similar to the one detected in pediatric Spanish (29) and Jewish patients (30), mostly comprised of children with PP. These different figures cannot be related to the different ethnicity of the populations studied, as the majority of the patients are of Caucasian origin.…”

“…The CYP21A2 genotyping of the 55 children affected by NCCAH showed that, as in other series, the most frequently observed mutation is V281L (23,29,30). Homozygosity for mild mutations was found in 52.7% of our patients, a percentage strikingly higher than that recently reported in a large series of French adult patients (26) and in previous studies in adult Brazilian patients (23), but similar to the one detected in pediatric Spanish (29) and Jewish patients (30), mostly comprised of children with PP.…”

Should 21-hydroxylase deficiency genotyping be considered in assisted reproductive technology programs?

“…Native acrylamide/bisacrylamide minigels were used to detect the 8-bp deletion. Complementary confirmatory sequencing of coding regions and intron-exon boundaries was also performed as previously described (8,17). Parental DNAs were also studied to determine allele segregation; this was further examined by complementary microsatellite typing (18,19) involving the highly informative D6S273 and D6S439 markers plus two intragenic intronic polymorphisms at tumor necrosis factor alpha and TAP1 (genes in the HLA region).…”

“…Some countries include this disorder in neonatal screening programs. The NC forms, which are associated with signs of hyperandrogenism, were initially described in adult women and only more recently in pediatric patients (4)(5)(6)(7)(8). Precocious pubarche and bone age advancement are typical in children; women may suffer hirsutism, acne, irregular menses, polycystic ovaries, and infertility.…”