ABSTRACT
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 aiiele 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] alleies in Iraqi Arab Muslims and Kurd Muslims and determine the genetic differences between them. 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. 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 inHLA-B. 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 outbreedmg 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
ABSTRACT
Iraq had more than twenty-four millions inhabitants of populations. This nation is one of the most populated countries in the world.it is difficult to define Iraqi populations genetically [HLA polymorphism] because they are structured of a mixture of many groups. [HLA phenotype frequencies that encoded by many closely. linked genes that are responsible for a variety of cell surface alloantigen proteins that are responsible for differences in different ethnic groups. .Arab Christians in Iraq. accounting for more than .three millions inhabitant mostly the northwest and other yurts of Iraq. This raised the need for a preliminary study of the HLA trend in this population. 1- Estimating the gene frequency of HLA class I [A. B. C w] and class 11 [DR and DQ] alleles in Iraqi Arab Christians. 2-Assessing the genetic relationship between Iraqi .Arab Christians and other Arabian, Asian and European populations. A total of underrated 568 Iraqi Arab Christians [AC] 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 phenotypes of all loci [AC]] were in agreement with Hardy-Weinberg equilibrium In case of. HLA-A locus. three variants dominate this locus A1 [0.123], A2 /[0.149] and .A3[0.134] which showed some similarities with Arabian .Asian and European people in the world. A3 had been found to be associated with Hereditary Hemochromatosis HHI but the risk increased when there is linkage disequilibrium between A3 B14. Fortunately B14 allele had a low frequency. In this group and common allele was B35 [0.154], and B5 [0.128] which had an association with Behcet's syndrome. So one can predict high incidence of this disease in this group of populntioin. Last locus was studied in class I was Cw4 that had a higher rate [0.173] in HLA Cw loci. In case of class II, it was done on small number of persons and the common allele was DR2 [53.84%] which is protective from insulin dependent diabetes mellitus disease while DQ1 is common allele in HLA-DQ loci. HLA typing of [AC] had some similarity with Arabian people because of their same ancestry and also had some similarly with Caucasoid Europeans because of outbreeding and intermixing with those populations due to migration
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]