This suggests a specific constellation of clinical traits linked to mutations at the COQ5 locus, so far, encompassing cerebellar ataxia, encephalopathy, developmental delay, short stature, dysarthria, ID, cerebellar atrophy, and COQ10 deficiency in leucocyte assay (Table 1: 2, 3, 5, 6, 9, 10, 29, 55, respectively). This evidence concerns the gene COQ5 and cerebellar ataxia.