ABSTRACT
The HLA region had been shown to be the most polymorphic genetic system in man. There is a variation in the frequencies of various HLA alleles between various populations. Estimating the gene frequency of HLA class I [A, B, Cw] and class II [DR and DQ] alleles in Iraqi Arab Muslims. Assessing the genetic relationship between Iraqi Arab Muslims and other Arabian, Asian and European populations. A total of 1400 unrelated Iraqi Arab Muslims [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. The distribution of HLA polymorphism [A, B, Cw, DR and DQ] was investigated in Iraqi Arab Muslims [AM]. It had been found that A2 was the most frequent allele in A Ioci [0.202], which is similar to other Arabian, Asian and European populations in the world. Other common allele was A1 [0.116]. The least frequent allele was A25 [0.003]. In case of B-locus, 851 was the most frequent allele [0.123]. This reflects the higher prevalence of Behcet's syndrome in Iraq and other Mediterranean countries. The other common allele was B35 [0.092] while rare alleles were B7, B8, B41, B44, B49, and B50. Those alleles showed shared comparable gene frequencies. Concerning HLA-Cw, the greater frequency was Cw4 and Cw7. Other class was class II, in this class; DR2 was the most frequent allele with a gene frequency was 0.153. It is a fortunately to have high level of this allele because it was a protective against insulin dependent diabetes mullets. The last locus was DQ; it had been found that DQ1 and DQ3 were the most frequent polymorphism [0.117 and 0.119, respectively]