SH2B3 and spinocerebellar ataxia type 2: These include, for RT, a locus on chromosome 12q24 containing the growth repressor SH2B3, and the RNA processing factor ATXN2, previously associated with a large number of disease susceptibilities including: type 1 diabetes, multiple sclerosis, spinocerebellar ataxia type 2, Parkinson's disease, longevity and many more.52 Phenotypically, processing speed and longevity are associated.63 Therefore, it is possible that this locus is influencing RT through its influence on a number of health traits.