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Older dads pass on more genetic mutations

Older dads pass on more genetic mutations
By starting families in their 30s, 40s and beyond, men could be increasing the chances that their children will develop autism and other diseases linked to new genetic mutations, say researchers.

It follows the new discovery that we inherit more than three times as many genetic errors from our father as from our mother.

And the rate of mutations goes up with the dad's age but not the mum's, the journal Nature reports.

For each year increase in the father's age at conception, the number of mutations increases by about two, the Icelandic researchers calculate.

This means that a dad who is 36 will pass on twice as many mutations to his child as a man of 20, and a 70-year-old father will pass on eight times as many.

Kári Stefánsson and colleagues at deCODE Genetics in Iceland compared the DNA of 78 families comprising a mum, dad and child.

On average, fathers passed on 55 mutations compared to 14 for mothers. Many of these DNA changes will be harmless, but others may not be.

A similar study by researchers at Harvard Medical School and published in Nature Genetics also found most mutations come from dad.

Experts already know that certain conditions, like autism, are more common among children with older fathers.

Scientists believe this could be explained by the fact that men make sperm continuously through their adult life, whereas women are born with all of the eggs they will ever possess to make a baby.

© Trio Media 2012

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