Language is acquired almost instinctively at an early age
UK scientists have identified the first gene involved in the development of speech and language.
The discovery could unlock the mystery of speech, a uniquely human characteristic.
The discovery was made by scientists in Oxford and London, using information from the Human Genome Project.
Professor Anthony Monaco from the Wellcome Trust Centre for Human Genetics in Oxford led the team. He said the information would be important for diagnosing language disorders and identifying other faulty genes.
"Language is a particularly human characteristic of which we know there are strong genetic influences when something goes wrong," he told BBC News Online.
"This is the first evidence of a particular gene that has been pinpointed as having a mutation leading to a language disorder."
Genetic detectives
The gene was found by studying three generations of a family affected by a rare language impairment.
Individuals suffering from the condition have difficulty understanding grammar and articulating speech.
Scientists now know that an error in the sequence of DNA letters in a gene called FOXP2 is to blame.
FOXP2 is thought to make a protein that controls other genes involved in speech and language.
It could lead researchers to other genes implicated in speech and language disorders, present in 4% of the population.
Professor Monaco is currently investigating whether FOXP2 is altered in other conditions involving language impairment such as autism. But he thinks the gene is just one "clue" in a complex puzzle.
Primate studies
The discovery could also shed light on how humans came to speak. Professor Monaco told BBC News Online that co-workers were already hunting for the same gene in chimpanzees and other primates.
Comparing the DNA letters of the same stretch of genetic code in humans and their closest living relatives could reveal how language evolved, he said.
The possibility that language has genetic roots was first raised in the 1960s.
Scientists argue that there must be a genetic basis to speech and language because it is universal, complex and acquired almost instinctively by children at a young age.
Professor Monaco's research, carried out in collaboration with a team at the Institute of Child Health in London, is published in the journal Nature.