[Fanconi anemia syndrome as a predisposing factor for acquired bone marrow aplasia]

A 4-year old girl who received prophylactic therapy with oral cephalexin for 1 year because of a history of urinary tract infections, was referred for evaluation of short stature. On physical examination mildly dysmorphic features were observed. Blood counts disclosed pancytopenia, and bone marrow examination showed hypoplasia of all 3 cell lines. Chromosome analysis after exposure to a DNA cross-linking agent (diepoxybutane) showed a chromosomal breakage pattern consistent with Fanconi anemia. Discontinuation of cephalexin was followed by improvement in hematological values. This course of events supports the hypothesis that acquired bone marrow depression may be a manifestation of Fanconi anemia, warranting the appropriate diagnostic work up in every case of acquired bone marrow aplasia.