Abstract

ABSTRACT: BACKGROUND: The HLA system is a relevant tool in population genetics analysis. From the genetic point of view, the HLA system is of general interest because of the extreme polymorphism of all known HLA loci. The allele and haplotype frequencies have a wide diversity among human population and differ in geographically and racially among populations. Iraq had a high percentage of Muslims people that distributed in two groups (Arab and Kurd). These groups are ancient populations and affected by many settlement in many centuries ago. These ancient settlements had left marks on the genetic structure of the modern Iraqi populations. The later immigrations to other countries were high in later years. The aim of study is to estimate the gene frequency of HLA class I (A, B, Cw) alleles in Iraqi Arab Muslims and Kurd Muslims and determine the genetic differences between them. METHODS: A total of unrelated 1400 Iraqi Arab Muslims (AM) and 705 Kurd Muslims (KM) healthy volunteers and individuals referred to Immunology and Tissue Typing Center in Al-Karamah Teaching Hospital for organ transplantation and Forensic medicine, were examined for HLA polymorphism using complement dependent cytotoxicity test from June-2003 to April-2004. RESULTS: The phenotypes of HLA typing of Iraqi Arab Muslims (AM) and Kurd Muslims (KM) were in agreement with Hardy-Weinberg equilibrium. Regarding HLA class I (A and Cw loci), there was a significant differences between these groups. Lasly, there was no significant difference between them in HLA-B. CONCLUSIONS: This may be due to their inhabitants different area in Iraq, and also due to their different origin as Arab and Kurd races with mild differences due to outbreeding and migration. The effects of invaders and settlements from out side the country and intermixing with them may play an important role in these differences