New Delhi, Jan. 24: In the first study of the genetics of autism in India, scientists in Calcutta have found that some fathers may transfer a version of a gene that makes their children susceptible to autism.
The researchers at the Manovikas Biomedical Research and Diagnostic Centre and other city institutions have found what they describe as a “possible paternal effect” that may underlie susceptibility to autism — a brain disorder marked by unusual behaviour and lack of communication abilities.
The scientists caution that their finding is based on a small sample of autistic children and will need to be verified through larger studies. “We don’t want anyone to jump to conclusions about a paternal role in autism, but this study raises issues that need to be explored further,” said Swagata Sinha, a psychiatrist at the Manovikas Centre and a member of the research team.
“We’re seeking clues to unravel the cause of autism — this is important for science and for parents with autistic children. Every parent wants to know the exact cause. And, at the moment, we have no answer to give them,” Sinha told The Telegraph.
The findings have been published this month in the journal American Journal of Medical Genetics: Neuropsychiatric Genetics.
Medical researchers have long suspected that autism is a multiple gene disorder with several genes and perhaps other unknown factors in the environment leading to the disorder.
“But it is also a highly heritable disorder — it can run in families,” said Usha Rajamma, a geneticist and principal investigator in the study.
The Calcutta researchers analysed sequences of a gene called reelin ina group of 73 autistic children and 80 children with no neurologicaldisorders as well as their parents who volunteered for the study.
Six years ago, scientists in Italy had shown that reelin may have a role in susceptibility to autism.
“The reelin gene is known to play a role in the development of thebrain and has been suspected to be a candidate gene involved inautism,” Rajamma said.
When Rajamma and her colleagues analysed reelin sequences in a group of 58 autistic children and their parents, they detected what they have described as “significant paternal transmission” of a particular variant of reelin.
“The reelin variant we’ve observed is very common in India, but byitself, it does not lead to autism,” Rajamma said. Autism is a multi-factor disorder and only when the right combination of all the susceptibility genes and the environmental factors are present does a person get autism, she said.
While there are no statistics from India, international studies suggest that 1 in 500 to 1 in 1,000 people have autism, indicating that India may have nearly two million autistic persons.