High level expression of N-acetylgluosamine-6-O-sulfotransferase is characteristic of a subgroup of paediatric precursor-B acute lymphoblastic leukaemia.

Microarray analysis is a powerful technology, but its impact on routine diagnosis for the near future maybe in revealing individual genes, which are useful diagnostic markers. Recently microarray analysis has identified a novel subgroup of childhood precursor-B acute lymphoblastic leukaemia (ALL) from a unique gene expression profile of over 30 genes. We have evaluated the four most highly expressed genes from this profile, by quantitative real time RT-PCR, to determine whether any of these genes by itself could be useful as a diagnostic indicator. The levels of expression of N-acetylglucosamine-6-O-sulfotransferase (GN6ST), protein tyrosine phosphatase receptor M (PTPRmu), G protein-coupled receptor 49 (HG38) and KIAA1099 protein were determined in childhood precursor-B ALL samples from a cohort of 116 Indian patients. In nine cases, three or four of these genes exhibited very high expression levels, but only GN6ST was consistently over-expressed. We suggest that very high level expression of GN6ST is a useful diagnostic marker for a subgroup of previously unclassified ALL.