Genes that influence height indentified

It seems to be a 'tall' story. Scientists claim to have developed a clearer picture of what makes some people stand head and shoulders above others.

They have identified a further 20 regions of the first common version of a gene, that has been linked to influencing height earlier, which together can make a difference of up to six centimetres.

Using DNA samples taken from over 30,000 people, the international researchers have identified the 20 loci (regions of genetic code) common variations of which actually influence adult height, the 'Nature Genetics' journal reported on Sunday.

'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.

'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,' said lead researcher Dr Tim Frayling of the Peninsula Medical School.

Half of the new loci identified by Dr Frayling and his colleagues contain genes whose functions are well documented.

While some 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.

Yet others are so-called 'master regulators', acting as switches to turn genes elsewhere in the genome on or off. 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.

However, of the twenty loci identified, the other half contain genes about which little or nothing is known.

The researchers have compared these findings to their work last year which identified the first common FTO gene for obesity. 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,' said co-researcher Dr Mike Weedon.