Human "Death Clock" Gene Search Narrowed
Chromosome region linked to length of aging- and cancer-related telomeres
Betterhumans Staff
11/4/2004 2:12 PM
The search for genes determining the length of human telomeres-cell "death clocks" linked with aging and cancer-has been narrowed.
Researchers Mariuca Vasa-Nicotera, Scott Brouilette and colleagues from the University of Leicester in the UK have linked differences in telomere length in humans to a region on chromosome 12.
They have also identified what they call a "strong candidate" gene, DDX11.
"Identification of the gene involved and elucidation of its mechanism of action could have important implications for our understanding of chromosomal assembly, telomere biology, and susceptibility to age-related diseases," they write.
Genetically determined
Telomeres are repeated DNA sequences that cap chromosomes. Each time a human cell divides, the cap shortens. When it gets too short, cells die. An enzyme called telomerase lengthens the cap.
Because aging has been linked to short telomeres and cancer has been linked to telomere lengthening, the length of telomeres has attracted much research attention.
Researchers have discovered that there is considerable variation in telomere length amongst humans, and that this variation appears to be strongly genetically determined.
To help locate underlying genes, the Leicester researchers examined 383 adults comprising 258 sibling pairs.
Analyzing telomere length (using telomere-restriction fragment analysis), they found a strong link to a locus on chromosome 12 that explained 49% of overall telomere length variability.
The research is reported in The American Journal of Human Genetics (read abstract).