The sizes of CAG repeats in AR ranged from 9 to 39, with 22 repeats as the most common allele (17.9%) in 736 ALS patients; among the 225 healthy controls, the sizes ranged from 11 to 34, with 22 repeats as the most common allele (20.4%) (Figure 1C). The gene discussed is AR; the disease is amyotrophic lateral sclerosis.