Mother’s Age May Affect Schizophrenia Risk

Researchers have found evidence of a significant overlap between genetic factors associated with schizophrenia risk and genetic factors associated with a mother’s age at first birth. They recently reported their findings in the online JAMA Psychiatry.

“We found that women with high genetic predisposition to schizophrenia tend have their first child at an early age or a later age compared with women in the general population,” said researcher S. Hong Lee, PhD, of the school of environmental and rural science, University of New England, Armidale, Australia.

The study used multiple independent genome-wide association study data sets. One came from a genome-wide association study involving 18,957 people with schizophrenia and 22,673 controls. The other genotyped cohort was 12,247 women from the community measured for age at first birth.

The genetic risk for schizophrenia for the women in the second cohort was estimated using genetic information inferred from the genome-wide association study, researchers explained.

When investigators compared the groups, evidence of a genetic overlap emerged apart from a mother’s psychiatric health or her partner’s age.

“We observed a U-shaped relationship between schizophrenia risk and age at first birth, consistent with the previously reported relationship between schizophrenia risk in offspring and maternal age when not adjusted for age of the father,” Dr. Lee said.

“The findings are relevant as previously the risk of schizophrenia in children associated with older mothers was generally thought to be caused by the age of the father and possible mutations in germ cells (sperm). This explanation may now need to be revisited.”

—Jolynn Tumolo

References

  1. Mehta D, Tropf FC, Gratten J, et al. Evidence for genetic overlap between schizophrenia and age at first birth in women. JAMA Psychiatry. 2016 March 23 [Epub ahead of print].
  2. Genetic link found between age at first birth and schizophrenia [press release]. University of New England: Biddeford, ME; March 24, 2016.