Marked down-regulation of nucleophosmin-1 is associated with advanced del(5q) myelodysplastic syndrome

This current study showed that down-regulation of NPM1 is rare or is not found in the 5q- syndrome and in other early MDS subtypes with the del(5q), but is common in advanced MDS with the del(5q) and is associated with the presence of a complex karyotype. These data support the hypothesis that reduced expression of NPM1 may play a role in the molecular pathogenesis of advanced MDS with the del(5q) and we suggest that this may be related to a concomitant increase in genomic instability in these cases.