Genome-wide analysis (GWA), the latest, highest-resolution genomic tool for studying the genetic roots of disease, requires collaboration among several fields. To analyse millions of datapoints, geneticists and clinicians must work with biostatisticians and bioinformaticians.

Such a team came together at the St Jude Children's Research Hospital in Memphis, Tennessee, to establish the roots of acute lymphoblastic leukaemia (ALL), the most common paediatric cancer.

Using patient samples from various studies done at St Jude, James Downing, chair of pathology at the hospital, and his team conducted GWA on 242 ALL-cell samples. They then compared 228 diagnostic bone-marrow samples from ALL patients with matched remission samples (see page 758). They reasoned that genomic differences found only in the former group represent somatic mutations that could contribute to pathogenesis.

They found that 40% of the ALL samples had abnormalities in genes that control B-cell development and differentiation. Downing thinks it might be possible to develop a small molecule to activate this pathway and trigger cell death in the leukaemic cells. “It's a different way of doing science,” he says of the GWA studies. “It can be challenging and it can be great fun.”