Follow-up by cytogenetic and fluorescence in situ hybridization analysis of allogeneic bone marrow transplantation in two children with Fanconi's anaemia in transformation

Results of bone marrow transplantation (BMT) in patients with Fanconi's anaemia (FA) in transformation are very poor and only a few cases with favourable outcome have been reported. We present the follow-up of two FA-myelodysplastic syndrome (MDS) patients with monosomy 7 and complex karyotype implicating chromosome 1. Both relapsed with acute myeloid leukaemia (AML) following an allogeneic BMT from an HLA-identical brother. The patients showed clonal cytogenetic evolution coinciding with the leukaemic transformation. In one patient, fluorescence in situ hybridization using X and Y chromosome probes detected an increase of host cells before clinical relapse. Both patients received a successful second allogeneic BMT from the same donor using a more intensive treatment regimen and remain in clinical and cytogenetic remission more than 3 years later.