title: High carrier frequency of 21-hydroxylase deficiency in Cyprus.
abstract: Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) is a common autosomal recessive disorder caused by mutations in the CYP21A2 gene. The carrier frequency of CYP21A2 mutations has been estimated to be 1:25 to 1:10 on the basis of newborn screening. The main objective of this study was to determine the carrier frequency in the Cypriot population of mutations in the CYP21A2 gene. Three hundred unrelated subjects (150 males and 150 females) from the general population of Cyprus were screened for mutations in the CYP21A2 gene and its promoter. The CYP21A2 genotype analysis identified six different mutants and revealed a carrier frequency of 9.83% with the mild p.Val281Leu being the most frequent (4.3%), followed by p.Qln318stop (2.5%), p.Pro453Ser (1.33%), p.Val304Met (0.83%), p.Pro482Ser (0.67%) and p.Met283Val (0.17%). The notable high CYP21A2 carrier frequency of the Cypriot population is one of the highest reported so far by genotype analysis. Knowledge of the mutational spectrum of CYP21A2 will enable to optimize mutation detection strategy for genetic diagnosis of 21-OHD not only in Cyprus, but also the greater Mediterranean region.
authors.affiliation: Department of Molecular Genetics, Function and Therapy, The Cyprus Institute of Neurology and Genetics, 1683, Nicosia, Cyprus.
authors.forename: A A P
authors.initials: AA
authors.lastname: Phedonos
authors.forename: C
authors.initials: C
authors.lastname: Shammas
authors.forename: N
authors.initials: N
authors.lastname: Skordis
authors.forename: T C
authors.initials: TC
authors.lastname: Kyriakides
authors.forename: V
authors.initials: V
authors.lastname: Neocleous
authors.forename: L A
authors.initials: LA
authors.lastname: Phylactou
mesh_terms: D000312:Adrenal Hyperplasia, Congenital / Q000453:epidemiology* / Q000235:genetics*; D003535:Cyprus / Q000453:epidemiology; D005260:Female; D005787:Gene Frequency; D006579:Heterozygote; D006801:Humans; D008297:Male; D009154:Mutation; D015995:Prevalence; D013255:Steroid 21-Hydroxylase / Q000235:genetics
chemical_list: C531510:CYP21A2 protein, human; D013255:Steroid 21-Hydroxylase
keywords: 21-hydroxylase deficiency; CYP21A2 gene; Cyprus; congenital adrenal hyperplasia