HLA class I alleles frequencies in the Syrian population

The HLA system is known to be the most polymorphic genetic loci in humans. Distribution and frequencies of HLA alleles are highly variable among different human ethnic groups. The HLA system has an important role in disease susceptibility and resistance, especially in autoimmune diseases and cancer. This study is the first report about HLA genetic variability and haplotypes among Syrians. Frequency of the HLA class I (A, B and C) alleles was determined in 105 healthy unrelated Syrian individuals from different regions in Syria. We also studied the associated haplotypes frequencies. Alleles frequencies were compared with those reported for other populations. Fifty-eight HLA class I alleles were observed in Syrians including 15 for HLA-A, 28 for HLA-B and 15 for HLA-C. We observed 37 HLA-A/C haplotypes, 32 B/C, and 31 A/B haplotypes. The most frequent haplotypes were A*01/C*04, A*02/C*07, A*02/B*35, and B*35/C*04. In conclusions, our preliminary study suggests a high variability in HLA class I alleles in the Syrian population. This study also gives a general reference database about the genetic pool distribution of HLA class I alleles among Syrians and can be consulted for HLA related diseases.