Researchers discovered that fathers are to blame for of the children’s rare diseases. More specifically, men’s DNA passes on four times as many new mutations than female DNA.
An Icelandic genetics company named deCODE came with this research that was led by researcher Kari Stefansson. The results revealed that mothers pass fewer genetic mutations than fathers.
Children with older fathers have a bigger risk of developing certain disorders
A previous research showed that the risk of having disorders such as intellectual abilities increases if the child has an older father. Allan Pacey, professor of andrology at Sheffield University, said: “We have known for many years that the risk of having a child with a medical condition of genetic origin increases noticeably with the father’s age at conception. It is for this reason that there is a recommended upper age limit for sperm donors, currently 40 years in the UK. Put simply, the genetic quality of sperm from younger men, in terms of new mutations, is generally much better than that of older men.” The new research may also shed some light on the results of the previous study.
Men pass on more mutations
The new study analyzed 14.00 Icelanders. It was discovered that women only pass new mutation for every three years of age, while men do that for every eight years of age. It appears that as the man ages, his sperm accumulates more and more mutations, while women are born with their full complement of eggs, and therefore they transmit fewer mutations to their children.
“It seems that when a chromosome breaks in an egg, it can sometimes be repaired, avoiding a chromosomal catastrophe but leaving a scar of small mutations,” said Martin Taylor, a geneticist at the University of Edinburgh.