NKG2C gene deletion in the Mexican population and lack of association to respiratory viral infections.

Expansion of a natural killer (NK) cell population that expresses NKG2C has been associated with cytomegalovirus and other viral infections. It has been suggested that this cell population may play a role in infection control. Deletion of the NKG2C gene (homozygous or heterozygous) has been reported with high prevalence in European and Asian populations. However, the effect of NKG2C genotype on NK cell responses to infection remains poorly defined. We determined the prevalence of the NKG2C deletion in a Mexican population (n = 300) and in a group of patients (n = 131) to assess whether NKG2C genotype affects the incidence of symptomatic viral infections caused by influenza or respiratory syncytial virus. The frequency of the NKG2C deletion haplotype in Mexican mestizos was significantly lower (10.3%) than that reported in other populations (17.5-21.9%). No difference in the prevalence of NKG2C deletion was observed in subjects with viral infections compared with the reference population. In addition, no differences in clinical characteristics and infection outcome were observed between patients with and without the NKG2C gene deletion. Our results indicate that copy number variation in the NKG2C gene has no impact on the severity of respiratory viral infections.