After pedigree verification, her brother affected by impaired hearing but without ataxia, was found to carry these two mutations in PTPRQ but only one heterozygous mutation in SYNE1, and all mutations in SYNE1 and PTPRQ were derived independently from two parents with normal phenotypes (Additional file 1: Fig. S1c). The gene discussed is PTPRQ; the disease is cerebellar ataxia.