The spectrum of neoplasms observed in WS can be compared with other recessive familial cancer predisposition syndromes associated with genetic instability such as Li-Fraumeni syndrome [26], [27]; the heritable bone marrow failure/cancer predisposition syndromes Fanconi anemia [28], [29], dyskeratosis congenita [30], Diamond-Blackfan anemia [31] and Shwachman-Diamond syndrome [32], [33]; and the heritable mismatch repair deficiency syndromes (e.g., homozygous mutations in MLH1 or PMS2) [34]. The gene discussed is PMS2; the disease is Bone marrow hypocellularity.