Deletion of chromosome 20 in bone marrow of patients with Shwachman-Diamond syndrome, loss of the EIF6 gene and benign prognosis

Shwachman-Diamond Syndrome (SDS; On-line Mendelian Inheritance in Man database number 260400) is an autosomal recessive disorder caused by mutations in the SBDS gene in at least 90% of cases (Boocock et al, 2003). It is characterized by exocrine pancreatic insufficiency, skeletal anomalies, and bone marrow failure with variable severity of neutropenia, thrombocytopenia and anaemia (Rothbaum et al, 2002). Acquired clonal chromosome anomalies are commonly found in the bone marrow (BM), being an isochromosome for the long arms of a 7, i(7)(q10), and a deletion of the long arms of a 20, del(20)(q11), the most frequent. The relationship between these chromosome changes and the risk of patients with SDS to develop myelodysplastic syndromes and acute myeloid leukaemia (MDS/AML) has been discussed (Dror, 2005). This risk increases with the age (Shimamura, 2006), and we have also shown that the acquisition of BM clonal anomalies is age-related (Maserati et al, 2009).