The actual percentage of cases with paternal germ line-derived schizophrenia in given population will depend on demographics of paternal childbearing
Is there going to be more violence because we have ignored the science of the male biological clock? If there is so much more autism, so much more diabetes type 1, how much more schizophrenia is there in the USA? Men could change the age they fathered babies if the knew the repercussions. There is the option for cryobanking sperm.
Schizophrenia Risk and the Paternal Germ Line
By Dolores Malaspina
Paternal age at conception is a robust risk factor for schizophrenia. Possible mechanisms include de novo point mutations or defective epigenetic regulation of paternal genes. The predisposing genetic events appear to occur probabilistically (stochastically) in proportion to advancing paternal age, but might also be induced by toxic exposures, nutritional deficiencies, suboptimal DNA repair enzymes, or other factors that influence the
fidelity of genetic information in the constantly replicating male germ line. We propose that de novo genetic alterations in the paternal germ line cause an independent and common variant of schizophrenia.
We initially examined the relationship between paternal age and the risk for schizophrenia because it is well established that paternal age is the major source of de novo mutations in the human population, and most schizophrenia cases have no family history of psychosis. In 2001, we demonstrated a monotonic increase in the risk of schizophrenia as paternal age advanced in the rich database of the Jerusalem Perinatal Cohort. Compared with the offspring of fathers aged 20-24 years, in well-controlled analyses, each decade of paternal age multiplied the risk for schizophrenia by 1.4 (95 percent confidence interval: 1.2-1.7), so that the relative risk (RR) for offspring of fathers aged 45+ was 3.0 (1.6-5.5), with 1/46 of these offspring developing schizophrenia. There were no comparable maternal age effects (Malaspina et al., 2001).