ASXL1 and myelodysplastic syndrome with single lineage dysplasia: ASXL1 exon 12 frameshift mutations (10 times the same p.Gly646Trpfsx12) were observed in 12 out of the 65 MDS cases (18.5%) including 1 out of 5 RA (20%), 2 out of 16 RAEB1 (12.5%) and 9 out of 19 RAEB2 (47.4%) (Additional file 1 Table S1).