Autism risk is greater if gran smoked

Research: Girls more likely than boys

Children are more likely to develop autism if their grandmothers smoked, a study has found.

The findings point to inherited effects on DNA strong enough to be felt across generations.

Girls appeared to be more susceptible than boys, according to the findings from 14,500 participants in the Children Of The 90s Study.

Exposure to tobacco toxins in the womb may have a harmful effect on developing eggs in a female foetus, scientists suspect.

This, in turn, could lead to the next generation having an increased risk of autistic behavioural problems.

Autism, which affects an estimated 700,000 people in the UK, is an umbrella term covering a wide range of disorders that impair communication and social skills and are associated with traits such as repetitive behaviour.

Rates of autistic spectrum disorder (ASD) have increased in recent years. One explanation is likely to be improved diagnosis, but experts believe environment and lifestyle have also played a role.

Professor Jean Golding, a senior member of the research team from the University of Bristol, said: “We already know that protecting a baby from tobacco smoke is one of the best things a woman can do to give her child a healthy start in life. Now we’ve found not smoking during pregnancy could also give their future grandchildren a better start too.

“We have started studying the next generation of participants, so eventually we will be able to see if the effect carries down from the great-grandparents to their great-grandchildren.”

The Children Of The 90s Study is charting the health of thousands of families living in the Bristol area from one generation to another.