Paternal Age Schizophrenia Risk Higher in Daughters of Old Fathers Some X linkage suggested

Daughters of older fathers are at increased schizophrenia risk according to Danish and US researchers suggesting that a new mutation on the X chromosome might be the cause of some cases of schizophrenia. Dr. Majella Byrne, of Aarhus University in Denmark, and colleagues found that men born when their father was aged 55 or more were at double risk of developing schizophrenia. In women, however the relationship was even stronger. The team found that women born to father aged 50 were more than twice as likely to develop schizophrenia. This increased to a nearly fourfold rsk in those born to fathers aged 55 or more.


Results Advanced paternal and maternal age was associated with increased risk of schizophrenia in univariate analyses. Controlling for socioeconomic factors and family psychiatric history, increased risk of schizophrenia was identified in those with a paternal age of 50 years or older. Sex-specific analyses revealed that the risk of schizophrenia was increased for males with fathers 55 years or older (incidence rate ratio [IRR], 2.10; 95% confidence interval [CI], 1.35-3.28); for females, the risk associated with paternal age was substantial for fathers aged 50 to 54 years (IRR, 2.22; 95% CI, 1.44-3.44) and 55 years or older (IRR, 3.53; 95% CI, 1.82-6.83).

Conclusion Increased risk of schizophrenia was associated with advanced paternal age, particularly in females, lending support to the theory that de novo mutations, possibly X-linked, associated with increased parental age might be responsible for some cases of schizophrenia.


From the National Centre for Register-based Research, Aarhus University, Aarhus, Denmark (Drs Byrne and Mortensen and Mr Agerbo); Institute for Basic Psychiatric Research, Psychiatric Hospital, Aarhus, Risskov, Denmark (Dr Ewald); and Department of Mental Hygiene, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Md (Dr Eaton).