Experts believe they are a little nearer to tracking down a gene which may influence how long you live. Belgian researchers say it is probably passed from fathers to daughters and mothers to sons on the sex chromosome. There is some evidence that suggests a reduction over time in the length of key pieces of DNA in the human cell may contribute to the diseases of old age. The research, in the Lancet, may help uncover the gene that controls this.
The precise reasons why people appear to age at different rates, and why some will die at a younger age, are likely to be highly complex. However, the relationship between the length of "telomeres" - which lie at the end of strands of DNA called chromosomes inside the nucleus of every cell - and this process, is becoming a little clearer, informs &to=http://www.bbc.co.uk' target=_blank>BBC
Ageing is widely believed to be governed by tiny nubs called telomeres, found at the end of chromosomes - the lengths of coiled DNA that contain genes. Every time a cell divides, the telomeres become shorter.. After successive cell replication, telomeres become so worn that no more divisions can take place, which means that tissue is not replaced when it reaches the end of its functional life.
Belgian scientists, reporting in the British medical weekly The Lancet, checked the telomere lengths in white-blood cells taken from several hundred volunteers in Flanders, northern Belgium. They discovered that telomere lengths were similar between fathers and daughters, mothers and sons, mothers and daughters and among siblings - but there was no similarity among fathers and sons or between spouses.
That points to an inherited cause, and more specifically the X chromosome, the researchers say. Females have two X chromosomes, both of which come from their parents; whereas males have an X, which is inherited from their mother, and a Y chromosome, which comes from their father. "Our observations suggest that the process of ageing might be an X-linked trait," the team, led by Jan Staessen of the University of Leuven, say, reports &to=http://www.channelnewsasia.com' target=_blank>ChannelNewsAsia