Cerebellar ataxia was more frequently caused by homozygous (62 cases, 33.7% of total pathogenic variant analysis) or compound heterozygous POLG1 mutations (75, 40.7%), while heterozygous mutations, i.e., dominant pathogenic variants, were rarely reported (10, 5.5%). The gene discussed is POLG; the disease is aceruloplasminemia.