Mutational analysis was performed using sequences of both strands of all of the PCR-amplified coding exons and the flanking intronic sequences of PLA2G6, PANK-2, SNCA, parkin, PINK-1, and DJ-1. Expansion of the CAG repeats of the SCA1, SCA3, DRPLA, and Huntington’s disease genes was also examined. The gene discussed is ATN1; the disease is Huntington disease.