FANCD2 and Friedreich ataxia: Moreover, evidence suggests that FANC pathway loss of function affects bone homeostasis and the skeletal system: FA patients display congenital abnormalities of the skeleton, mesenchymal tissue-derived malformations, and osteoporosis [49] partially recapitulated in embryos and/or adult Fancc−/−, Fancg−/−, Fancd2−/− and Fancc−/−–Fancg−/− double-KO (DKO) mice.