FANCA and Friedreich ataxia: The similar sensitivity to DNA crosslinking agents of FA cells from at least 21 complementation groups known so far [FANC-A, B, C, D1, D2, E, F, G, I, J, L, M, N, O, P, Q, R, S, T, U and V7, 10, 11, 14–24], and common clinical symptoms suggest that the all FA proteins function in a common signaling transduction pathway (the FA pathway).