XRCC2 and Bone marrow hypocellularity: Developmental defects, early-onset bone marrow failure and high predisposition to cancer. Impairment in follicular development due to defective oocyte meiosis and abnormal germ cell development with PA or SA.FANCA (*607139), FANCL (*608111), FANCM (* 609644), FANCU (*600375), FANCD1 (*600185) are occasionally described in isolated POI (principally SA)