Most men develop tiny clumps of mutant cells in their testicles as they age

A rare form of testicular tumour has provided scientists at the University of Oxford and Copenhagen University Hospital with new insights into how genetic changes (mutations) arise in our children. The research could explain why certain diseases are more common in the children of older fathers.

Researchers describe a surprising link between certain severe childhood genetic disorders and rare testicular tumours occurring in older men: the germ cells that make the mutant gene-carrying sperm seem to be the same cells that produce the tumour.

The work was published today in Nature Genetics.