Men have higher rates of bowel cancer than women because of a genetic fault in the female sex chromosome, British experts said Monday.
In an international collaboration led by the Institute of Cancer Research (ICR), scientists suggested that the development of the disease can be linked to a defect in the X chromosome that is associated with lower levels of a gene called SHROOM2, which controls how cells develop and take shape.
The fault can occur in both genders, but because females have two X chromosomes, one faulty version is masked by the normally-functioning version. This is not possible in men, who have only one X chromosome, paired with a Y chromosome.
Professor Richard Houlston from the ICR said, "To our knowledge, this is the first time that anyone has shown that one of the sex chromosomes is involved in the development of a cancer that can afflict both sexes."
He added, "This may help explain why bowel cancer is slightly more common in men. Ultimately, it could also help us target screening to those who are more at risk of the disease."
The study, which also involved research from the universities of Oxford and Edinburgh, was published in the journal Nature Genetics.