Furthermore, research has revealed a strong effect of ATXN2 expansion on Parkinson disease (PD) and the MSA-P subtype9, and intermediate-expansion within ATXN1 or ATXN2 has been associated with an increased risk for amyotrophic lateral sclerosis (ALS)10. The gene discussed is ATXN1; the disease is amyotrophic lateral sclerosis.