The frequency of the functional polymorphism, T2437C transversion (Met-->Thr), in the HSP 70-Hom gene was investigated within a healthy aged Irish population using oligonucleotide probes. The 2437T polymorphic nucleotide was observed to increase in the elderly, although not attaining statistical significance. The TT genotype was observed to be significantly increased within the Irish aged population (p=0.03), while conversely the TC genotype was significantly decreased in the aged subjects (p=0.01). These findings would support the theory that the change from a Met (non-polar and hydrophobic) residue to a Thr (polar and neutral) residue may disrupt the peptide-binding specificity of HSP 70-Hom and have an effect on its functional efficiency. One postulates that the highly significant p-value obtained for the TC genotype may infer that the presence of both the T and the C allele (heterozygosity) resulting in the generation of two different HSP 70-Hom protein species may negatively influence longevity.