The older the father, the more mutations in children
A study of Nature has revolutionized some myths about the age of the father and mother in procreation. They transmit few mutations to their children. Instead parents pass and most mutations increase with age of the father. This research sheds light on the relationship between paternal age and diseases like autism and schizophrenia.
Traditionally, the mother has blamed the problems of the children. In the past, were repudiated and even put to death for not providing the seed that the father wanted. But according to the new study, the first mutations responsible for the children’s father.
The study has sequenced the genome of 78 trios composed of father, mother and son. Comparing genomes have been searched novo mutations, ie those present in the child but not the father nor the mother and therefore have been generated in the sperm, egg or embryo. Study data are inconclusive.
Parents spend four times more mutations to their children than mothers: on average 55 versus 14. Mutations father passes increase exponentially with age. At age 36 passed twice mutations while the 70 eight times. An Icelandic children born in 2011 will have 70 new mutations compared with a child born in 1980 to be 60. The age of the parents has happened in that period of 28 to 33.
The reason that most mutations generated parents with age is that the spermatozoa are constantly generated. Each new division of primordial cells at risk of producing a mutation that adds to the above. The case of women is different: it is born with all the eggs for life.
Most mutations are harmless. Some however can be lethal. This study does not prove but it seems to relate paternal age with increasing diseases like autism and schizophrenia. These are complex diseases that affect a single gene mutations but the increase is a clear risk factor. Another important aspect is that, in humans, most of the genes are expressed in the brain.
A final aspect of this fascinating study relates to human evolution . The mutations not only cause disease. Some produce individuals better adapted to the environment, more evolved. Analyzing the mutation rate we conclude that l human evolution has been faster than expected. Until now we thought that we split from chimpanzees between 7 and 11 million years. with the new study may be that the age difference is between 4 and 7 million years.
As the author of the study, the elderly may be negative father for the next generation, but is good for the future of our species.Tags: evolution, Genetics, Neuroscience