Variations in short tandem repeats deduced on the basis of the number of repeats and the relationship of these variations with longevity.

The objective of this study was to investigate the quantitative characteristics of short tandem repeat (STR) variations deduced on the basis of the number of STRs that are beneficial for human survival. The longevity group included 60 nonagenarian subjects, and the control group included 250 reference adults (age, 20-50 years). Alleles of 15 Combined DNA Index System STR loci were determined using a commercial polymerase chain reaction kit. An STR with the highest frequency distribution in a population (control group) was considered as a conservative STR, and the number of core unit repeats of this STR allele was considered as the median repeat number in the STR locus (STRm). The absolute difference between the STRm and the number of core unit repeats of other STR alleles can be considered as the quantitative marker of variation for that particular STR allele (M value). The mean M values of CSF1TPO in the longevity group were significantly higher than those in the control group (P < 0.05). These findings appear to suggest that at least one of the STR loci may be associated with longevity. The M value of STR may be a new and high-efficacy genetic marker.