Adrenal 21-hydroxylase gene mutations in Slovenian hyperandrogenic women: Evaluation of corticotrophin stimulation and HLA polymorphisms in screening for carrier status

Abstract

Objective: To study the incidence of 21-hydroxylase deficiency in Slovenian hyperandrogenic women, at the gene level. Previous endocrine studies indicated large differences in the incidence of 21-hydroxylase deficiency in hyperandrogenic women. The predictive values of the 17- hydroxyprogesterone (17-OHP) response to ACTH stimulation and of HLA typing in screening for carrier status were re-evaluated. Design: Molecular analysis of CYP21 gene, ACTH stimulation and human leucocyte antigen (HLA) typing were performed in 83 consecutive Slovenian hyperandrogenic women. Measurements: Cortisol and 17-OHP concentrations were measured at baseline and 60 min after ACTH stimulation. Basal adrenal androgen concentrations were also measured. Results: None of 83 hyperandrogenic patients was affected with non-classical 21-hydroxylase deficiency, but 12 of 81 patients (14.8%) had high concentrations of 17-OHP after stimulation, indicative of carrier status. The increase in 17-OHP concentrations could be explained by a carrier status for CYP21 gene mutations in only three of 12 patients (25%), whereas seven of 69 patients (10.1%) with normal concentrations of 17-OHP after stimulation were found to be carriers of CYP21 gene mutations, indicating low positive predictive values of ACTH stimulation as a screening test for carriers of 21- hydroxylase deficiency. In total, 11 carriers were identified among 83 patients: seven CYP21 gene deletions/conversions, two Gln318Stop and one Val281Leu mutation and one gene conversion extending from exon 4 to exon 7 were found. The association between Val281Leu mutation and HLA-B14 antigen was confirmed in this Slovenian population. Conclusions: Basal or ACTH- stimulated 17-OHP concentrations are not a good indicator of the carrier status for 21-hydroxylase deficiency among Slovenian hyperandrogenic patients. Reliable screening for carriers of 21-hydroxylase deficiency is possible only by molecular analysis of the CYP21 gene.