The largest study of its kind has linked two inherited genetic variants with an increase in susceptibility to the most common form of childhood leukaemia.

One variant is linked with higher rates of relapse and poorer overall survival - an important discovery which could lead to new drugs for children who do not respond well to current treatments.

The study by scientists at The Institute of Cancer Research, London, analysed the genomes of over 1,500 children with leukaemia and 4,500 healthy children.

Overall survival for childhood acute lymphoblastic leukaemia (ALL), a cancer of the white blood cells, is now very high, with up to 90% of children being cured.

A minority of patients, however, still do not respond to standard treatment.

The research, published online in the journal Blood, was principally funded by charities Leukaemia & Lymphoma Research and the Kay Kendall Leukaemia Fund, with additional support from Cancer Research UK.

The study strongly linked two common single nucleotide polymorphisms (SNPs), single letter ‘copying errors’ in DNA, with susceptibility to leukaemia. One of these SNPs, rs3824662 in the gene GATA3, was associated with a tumour subtype having two-fold higher rates of relapse and poorer overall survival figures.

Study leader Professor Richard Houlston, Professor of Molecular and Population Genetics at The Institute of Cancer Research (ICR), said: “This is the first unambiguous evidence that for the most common form of childhood leukaemia inherited susceptibility also influences tumour subtype and associated clinical outcome.”

Professor Chris Bunce, Research Director at Leukaemia & Lymphoma Research, said: “These findings provide further insights into the genetic and biological basis of inherited genetic susceptibility to childhood acute lymphoblastic leukaemia. By understanding how different genetic variations determine cancer subtype, we can tailor treatment accordingly.”

Source: ICR