Table of Contents Author Guidelines
Enzyme Research
Volume 2016, Article ID 9040616, 7 pages
http://dx.doi.org/10.1155/2016/9040616
Research Article

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

1Genetic Counseling Clinic and Genetics Laboratory, The Teaching Laboratories, Medical City, Baghdad, Iraq
2Department of Pathology, College of Medicine, Baghdad University, Baghdad, Iraq
3Department of Pediatrics, College of Medicine, Baghdad University and Pediatric Endocrine Consultation Clinic, Children Welfare Hospital, Baghdad, Iraq
4ViennaLab Diagnostics GmbH, Gaudenzdorfer Guertel 43-45, 1120 Vienna, Austria
5National Center of Hematology, Al-Mustansiriya University, Baghdad, Iraq

Received 12 June 2016; Accepted 31 August 2016

Academic Editor: Hartmut Kuhn

Copyright © 2016 Ruqayah G. Y. Al-Obaidi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

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.