London (PTI): Scientists have pinpointed a gene, which they claim is behind a common language disorder in kids, a finding that could lead to better diagnosis and treatment.

It has long been suspected that genes are involved in specific language impairment that causes delayed speech, poor comprehension of language and an inability to link words into grammatical structures and sentences.

Now, a team at Oxford University has found variations in a gene called CNTNAP2 are associated with specific language impairment (SLI), which causes communication difficulties in many children.

"CNTNAP2 is the first one we have been investigated in SLI and it looks like it is indeed involved in common language deficits," team leader Simon Fisher told The Times'.

In fact, the discovery has emerged from studies of another language-related gene called FOXP2 that's a biological "master switch" which causes severe but rare communication defects when it goes wrong.

And, according to Fisher, the discovery can be used to identify separate types of SLI that respond to different methods of speech and language therapy, or even to new drugs.

"Any new information will be helpful because at the moment, it's very difficult to sub-type SLI. It would be good to identify people who are at risk, as early identification is really important. It seems to be an effective way of actually improving outcomes, through speech and language therapy.

"There isn't a magic bullet, but we're hoping that by understanding the biology more it'll help people to come up with new therapies. If you can identify pathways in the brain that contribute, you may be able to figure out how to improve them," Fisher said.

The findings are published in the latest edition of the New England Journal of Medicine.