Although the ALS/FTD phenotype is caused by a GGGGCC hexanucleotide repeat expansion in C9ORF72, an ATTTC repeat insertion in a large ATTTT repeat in DAB1 was found to be the cause of the SCA phenotype in the other patients, allowing for a diagnosis of ATX‐DAB1 (SCA37 locus). The gene discussed is DAB1; the disease is autosomal dominant cerebellar ataxia.