British researchers say they’ve narrowed the search for the ‘death clock’ gene thought to be key to cancer, aging and age-related diseases.The University of Leicester scientists studied the genetics of 383 adults, and say they have located a strong candidate for the gene in a region on Chromosome 12.The ‘death clock’ gene controls the length of human telomeres. These are repeat DNA sequences that cap a chromosome. Every time a human cell divides, this cap shortens, and when the cap gets too short, cells die. There’s great variation in the length of telomeres that people are born with.The findings appear in the current issue of The American Journal of Human Genetics.