FA can be caused by biallelic mutations in the majority of the genes, hemizygous mutations in FANCB, or by dominant negative mutations in RAD51. Over the last 2 years, five new FA genes were discovered, such as FANCR/RAD51, FANCS/BRCA1, FANCT/UBE2T, FANCU/XRCC2, and FANCV/MAD2L2/REV7. This evidence concerns the gene FANCB and Friedreich ataxia.