AR and Kennedy disease: The healthy individuals normally carry 9 to 36 CAG repeats, while the individuals affected with SBMA have 38 to 62 CAG repeats in AR. The disease symptoms occur around 30 to 50 years of age (Kennedy et al., 1968; Atsuta et al., 2006) with a strong correlation between the age of disease onset and CAG repeat length (Igarashi et al., 1992; Atsuta et al., 2006).