Another patient showed a paracentric inversion of a chromosome 1 as acquired clonal anomaly in the BM: we postulated that it caused AA due to a position effect acting on the gene MPL, severely hypo-expressed, with a final diagnosis of Congenital Amegakaryocytic Thrombocytopenia (CAMT) [5]. This evidence concerns the gene MPL and congenital amegakaryocytic thrombocytopenia.