We found several somatic hemizygous mutations in del(5q) cases, including G3BP1 and CSNK1A1. Mutations in CSNK1A1 were found in a canonical E98 position as recently reported [16, 25]; only hemizygous mutations were found with del(5q) in the context of various clinical subtypes, including aggressive diseases RAEB-1 or therapy-related MDS. This evidence concerns the gene CSNK1A1 and myelodysplastic syndrome.