Recently, a heterozygous GGC repeat expansion coding for a polyglycine (polyG) within the zinc finger homeobox 3 gene (ZFHX3; MIM 104155) was identified in SCA4 pedigrees [4–7] using long-read genome sequencing (LR-GS), ZFHX3 encodes a transcription factor with multiple homeodomains and zinc finger motifs. The gene discussed is ZFHX3; the disease is spinocerebellar ataxia type 4.