[Prevalence of C77G polymorphism in exon 4 of the CD45 gene in the Spanish population].

A mutation (C77G) in exon 4 of the CD45 gene is the most common cause of CD45 abnormal splicing in European populations, which has been associated with an increased susceptibility to human immunodeficiency virus infection. We aimed to analyze the C77G frequency in the Spanish population. 517 healthy donors. CD45RA and RO expression was determined in circulating T lymphocytes by flow cytometry. CD45 exon 4 sequencing was carried out in individuals with an abnormal coexpression of CD45 isoforms. 6/517 individuals presented CD45RA persistence on memory T cells; all of them were heterozygous for C77G mutation. The resulting allelic frequency was 0,58% (95% confidence interval, 0.23-1.32). C77G is present in the Spanish population. Further studies to elucidate its clinical significance are needed.