Genetically, FA is characterized by the defects in one or multiple of the 23 FANC proteins (FA subtype proteins) from FANCA through FANCY The disease follows autosomal recessive pattern with 21 genes involved, including: FANCA, FANCC, FANCD1/BRCA2, FANCD2, FANCE, FANCF, FANCG/XRCC9, FANCI, FANCJ/BRIP1, FANCL, FANCM, FANCN/PALB2, FANCO/RAD51C, FANCP/SLX4, FANCQ/ERCC4, FANCS/BRCA1, FANCT/UBE2T, FANCU/XRCC2, FANCV/REV7 and FANCW/RFWD3, FANCY/FAP100 (Ceccaldi et al., 2016; Niraj et al., 2019; Lipton et al., 2020; Moreno et al., 2021; Repczynska et al., 2022). The gene discussed is ERCC4; the disease is Friedreich ataxia.