In the study focussing on SMAD4, a tumour suppressor gene implicated in pancreatic and colorectal cancer, the researchers found that such genes don't really need both alleles to be knocked out before disease phenotypes are expressed.
Led by Riccardo Fodde from Erasmus MC, Rotterdam, the researchers found that only one allele of SMAD4 has to be damaged to put a person at risk of pancreatic and colorectal cancer.
They found that having one mutated SMAD4 allele was associated with the development of gastrointestinal polyps.
This is the first study to deal with the molecular and cellular consequences of SMAD4 damage on a genome-wide scale.
The study was published in BioMed Central's new open access journal PathoGenetics.