Taken together, these findings demonstrate that defects occur in both of ERCC4 and ERCC1 can result in either CS or the combined XP‐CS‐FA phenotype (Kashiyama et al., 2013).In this regard, the question that arises is that whether the severe skeletal abnormalities result from the FANCJ or ERCC6 mutation. This evidence concerns the gene ERCC4 and Friedreich ataxia.