The Spectrum of Genetic Defects in Congenital Adrenal Hyperplasia in the Population of Cyprus: A Retrospective Analysis

Horm Metab Res. 2019 Sep;51(9):586-594. doi: 10.1055/a-0957-3297. Epub 2019 Sep 10.

Abstract

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) is caused by mutations in the CYP21A2 gene. The study refers to CAH patients of Greek-Cypriot ancestry between years 2007 and 2018. One hundred and twenty patients with various degrees of CAH were categorized and genotyped. The patients were categorized in 4 mutation groups based on their clinical and biochemical findings. The majority of patients (85.0%) belonged to the non-classic (NC)-CAH form and the disorder was more often diagnosed in females (71.7%). The most severe classic salt-wasting (SW) form was identified in 11 neonates (9.2%). Seven (5.8%) children were also identified with the simple virilizing (SV) form and a median presentation age of 5 years [interquartile range (IQR) 3.2-6.5]. In the 240 nonrelated alleles, the most frequent mutation was p.Val281Leu (60.0%) followed by c.655 A/C>G (IVS2-13A/C>G) (8.8%), p.Pro453Ser (5.8%), DelEx1-3 (4.6%), p.Val304Met (4.6%), and p.Gln318stop (4.2%). Other less frequent mutations including rare deletions were also identified. Following our recent report that the true carrier frequency of CYP21A2 in Greek-Cypriots is 1:10, this study reports that the CAH prevalence is predicted around 1.7 cases per 10 000 people. Therefore, the up-to-date 120 CAH patients identified by our group make only the 6.9% of the ones estimated (approximately 1750) to exist in the Greek Cypriot population. The compiled data from a coherent population such as the Greek-Cypriot could be valuable for the antenatal diagnosis, management and genetic counselling of the existing and prospect families with CAH.

MeSH terms

  • Adrenal Hyperplasia, Congenital / enzymology
  • Adrenal Hyperplasia, Congenital / genetics*
  • Alleles
  • Child
  • Child, Preschool
  • Cyprus
  • Female
  • Genotype
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Mutation
  • Point Mutation
  • Retrospective Studies
  • Steroid 21-Hydroxylase / genetics*
  • Steroid 21-Hydroxylase / metabolism

Substances

  • CYP21A2 protein, human
  • Steroid 21-Hydroxylase

Supplementary concepts

  • Congenital adrenal hyperplasia due to 21 hydroxylase deficiency