Smoking gran link

Study finds autism risk

CHILDREN are more likely to develop autism if their maternal grandmother smoked during pregnancy, researchers say.

A study of grandparents’ smoking has found the effects may skip a generation, increasing a grandchild’s risk of being autistic by 53 per cent.

Bristol University scientists said the risk was greater for girls, who were 67 per cent more likely to display autistic traits if their maternal grandmother smoked.

One possible cause is believed to be DNA damage caused by smoking and passed down through mitochondria, the ‘powerhouses’ of body cells. Mitochondria reach the next generation via a mother’s egg, which can affect her daughter’s eggs while she is in the womb.

When the daughter has children, the genetic inherit- ance from her mother’s smoking could be passed on.

Girls may display more autistic traits as a result because gender differences mean the genes from their grandmother may have no effect on boys’ behaviour.

Professor Jean Golding, coauthor of the study which involved 14,500 people, said: “We already know protecting a baby from tobacco smoke is one of the best things a woman can do to give her child a healthy start.

“Now we’ve found not smoking during pregnancy could give their future grandchildren a better start. Eventually we will see if the effect carries down from greatgrandparents.”

The research used a ‘children of the 90s’ study to look at grandmothers who smoked during pregnancy, with an average age of 54 at the birth of their grandchildren, whose records were examined up to age 11.