No evidence of CNS atrophy was reported in four inherited ataxias: three dominant including SCA41 (OMIM 616410), SCA46 (OMIM 617770) and spastic ataxia type 1 (SPAX1, OMIM 108600), and one recessive, namely SCAR23 (OMIM 616939). The gene discussed is PLD3; the disease is cerebellar ataxia.