Taipei: Scientists in Taiwan have used genome sequencing to show that men who become fathers at a later age are more likely to pass along new mutations that put their children at a higher risk of developing schizophrenia.

According to Focus Taiwan, the study was conducted by researchers at the National Health Research Institutes (NHRI) and National Taiwan University and was published in the scientific journal Molecular Psychiatry in March. At a press conference, NHRI Vice President Wei J. Chen highlighted that while geriatric pregnancies have been extensively studied, there is less research on the impact of paternal age on children's health.

Wang Shi-heng, an assistant researcher at NHRI's National Center for Geriatrics and Welfare Research, explained that the NHRI had previously examined links between paternal age and schizophrenia by analyzing over 7 million Taiwanese medical records. The findings indicated that children whose fathers were aged 25-29 at birth had a 0.5 percent chance of developing schizophrenia, compared to a 1 percent chance for those born to fathers aged 50 or above.

Further examination showed that if the grandfather on either side was also older at the time of the parent's birth, the child's risk increased even more. Wang suggested two explanations: one being that men with a higher risk of mental illness tend to have children later, and the other that older fathers are more likely to pass on new gene mutations due to continuous sperm cell production.

The NHRI team further investigated by performing whole-genome sequencing on five Taiwanese families with three siblings affected by schizophrenia and two healthy parents. Their research found that each year a man delayed having children, the child had 1.5 times more new gene mutations. Additionally, more mutations correlated with an earlier onset of schizophrenia symptoms.

Their analysis showed that 30 percent of the association between paternal age and schizophrenia onset is mediated by paternal age-related mutations, with the remaining 70 percent attributed to familial and social factors. Chen also noted that paternal age below 20 is linked to other risks for the child.

These findings emphasize the need for government policies encouraging couples to have children at suitable ages. In Taiwan, Interior Ministry data shows that from 1991 to 2023, the average age of mothers at childbirth rose by 5.2 years from 27.2 to 32.4, while the average age of fathers increased by 4.3 years from 30.3 to 34.6.