London, April 7 : Scientists have identified dozens of genes and genetic regions that influence height in humans.
This advancement results from the efforts of a team of researchers-including Dr. Tim Frayling from the Peninsula Medical School, Exeter, and Professor Mark McCarthy from the University of Oxford.
It is the same team that, last year, identified the first common gene variant to affect height, though the gene made a difference of only 0.5 centimetres.
In the present study, the researchers used DNA samples from over 30,000 people, many taken from the Wellcome Trust Case Control Consortium-the largest study ever undertaken into the genetics underlying common diseases-and from the Cambridge Genetics of Energy Metabolism (GEM) consortium and the CoLaus Study in Switzerland.
Their study led to the identification of 20 loci (regions of genetic code), common variations of which influence adult height.
"The number and variety of genetic regions that we have found show that height is not just caused by a few genes operating in the long bones. Instead, our research implicates genes that could shed light on a whole range of important biological processes," Nature Genetics quoted Dr. Frayling as saying.
"By identifying which genes affect normal growth, we can begin to understand the processes that lead to abnormal growth - not just height disorders but also tumour growth, for example," adds the researcher.
Half of the new loci identified by the research team contain genes whose functions are well documented.
The researchers say that some of these genes help regulate basic cell division, which may have implications for cancer research.
Other genes are implicated in cell-to-cell signalling, an important process in the early development of embryos in the womb, they add. The researchers call these genes "master regulators" that act as switches to turn genes elsewhere in the genome on or off.
The researchers have revealed that one locus in particular is also implicated in osteoarthritis, the most common form of arthritis involving the effects of wear and tear on the body's structures. According to them, this locus may be involved in the growth of cartilage.
Dr. Frayling, however, says that 50 per cent of the 20 loci identified by the research team contain genes about which little or nothing is known.
The researchers compare these findings to their work last year which identified the first common gene for obesity, the FTO gene. Even though the gene has been shown without a doubt to be influence body size, its role is still unclear.
"There may be more than a hundred genes which affect our height, many of which will work in surprising or unpredictable ways. The challenge now for us is to understand how they influence growth in the body. This could open up new avenues for treating a range of diseases," says Dr Mike Weedon, lead author on the paper.