FAAP20 and Friedreich ataxia: When it comes to molecular analysis of the FA patients and the severity and course of the disease, according to the presence of FANCA variants, FANCA: c.3445_3448dup variant is a frameshift variant resulting in a premature stop codon and a truncated protein (241 aa shorter).The missing N-terminal region of the protein, is necessary for the interaction between FANCA and Fanconi Anemia Associated Protein 20 (FAAP20), the stability of whose is essential for the proper function of FA/BRC pathway and the accurate response to crosslink damage.