It’s commonly believed that women have a biological clock that starts between the ages of 30 and 35, but research now suggests that men may have one too. Researchers found in a recent study that as men age, the chances of passing on autism or schizophrenia increase. The biological clocks of men and women work differently.
When a woman is born, she has a fixed number of eggs and as she gets older, not only does the quantity of eggs decrease, but also the quality. This can lead to eggs having the wrong number of chromosomes, leading to birth defects and conditions such as Down syndrome.
Men, on the other hand, transmit genetic mutations and the number of mutations seems to increase with age. The study found that the father’s sperm transmit an average of 55 mutations, far more than the 14 from the mother’s egg. Researchers believe this is because men create sperm during their lifetime. These mutations can lead to the transmission of serious illnesses to the child, including autism and schizophrenia.
This would correlate with findings that as men age, the number of mutations increases dramatically. A man in his early twenties would go through an average of 39 mutations, but that number nearly triples by age 40 to 90 mutations. Based on the results of the study, the researchers were able to estimate that the frequency of mutations in a man’s sperm increases twice every 16 years.
Source: The Conversation