Genetics: Inbreeding and associated health outcomes

Insights into inbreeding and its potential effects on health are presented in an analysis published in Nature Communications.

Loic Yengo and colleagues estimated the prevalence of extreme inbreeding - mating between first- and second-degree relatives (for example, parents and their offspring or half - siblings) - using anonymized data from 456,414 individuals in the UK Biobank. The authors did so based on runs of homozygosity (identical stretches of the genome that must have been inherited from both mother and father) and tested whether this was associated with a number of health outcomes.

Among the participants included in the study, the authors found 125 individuals whose genetic data suggested that they were offspring of first- or second-degree relatives. The authors also found that in this cohort, extreme inbreeding was associated with negative health consequences, such as reduced lung function, visual acuity or cognitive function, which confirms previous findings. In addition, they showed that offspring resulting from inbreeding had a general higher risk of disease.

The authors note that the data have to be interpreted with caution because of the small number of extreme inbreeding cases and the likely recruitment bias in the UK Biobank (proportionally, participants in the UK Biobank tend to be healthier and have a higher level of education than the rest of the population).