Consanguineous parentage raises risk of mood disorders, psychoses in offspring

While Charles Darwin – himself the product of a consanguineous marriage – found no evidence of a higher prevalence of consanguineous parentage among the inmates of asylums in England, there is known to be a higher risk of recessively inherited single-gene disorders among the offspring of consanguineous couples. However, until now, it was not known whether this also included an elevated risk of psychiatric disorders.

The findings of this study should stimulate further research efforts toward a greater understanding of the genetic contribution to common complex psychiatric conditions. The increase in whole-genome sequencing could provide entire genomes to help guide genetic counseling, not only for medical but also psychiatric conditions.

The study also should raise awareness about the difficulties and challenges associated with determining consanguinity, amid the potential stigma associated with cousin marriage.

Alison Shaw, DPhil, is affiliated with the department of social anthropology at the University of Oxford (England). These comments are taken from an accompanying editorial (JAMA Psychiatry 2018. Apr 4. doi: 10.1001/jamapsychiatry.2018.0513). No conflicts of interest were declared.