Shirin Farjadian*, Sepide Namdari, Mohammad Reza Bordbar, Omid Reza Zekavat
Acute Lymphoblastic Leukemia (ALL) is known to be the most common malignancy among children. The early onset of ALL suggests a key role of genetic factors in its development. Killer Cell Immunoglobulin-like Receptor (KIR) gene complex that encodes a group of key receptors expressed at the surface of natural killer cells has been of great interest as a possible genetic factor affecting the susceptibility to ALL. In this case-control study, we aimed to verify whether the inheritance of specific KIR genes or genotypes were associated with susceptibility to childhood B-ALL in southwestern Iranian population. To this end, KIR genotyping was carried out for 120 patients with childhood B-ALL and 170 unrelated healthy controls using PCR-SSP method. The frequencies of 11 KIR genes and KIR2DS4 variants were investigated among patients and healthy controls. We found no association between KIR genes and genotypes, centromeric and telomeric genotypes as well as the number of activating or inhibitory KIRs and susceptibility to childhood B-ALL. Moreover, no association between childhood B-ALL and KIR B-content scores was detected. However, AA genotype carriers homozygous for KIR2DS4 deleted variant were found to be at a higher risk of developing childhood B-ALL compared with those who inherited at least one KIR2DS4 full-length variant. It seems that the inheritance of different KIR genes does not affect the risk of childhood B-ALL in southwestern Iranian population. However, among individuals with AA genotype, homozygosity for KIR2DS4 deleted allele seems to increase the risk of childhood B-ALL.