Influence of autozygosity on common disease risk across the phenotypic spectrum
Daniel Malawsky, Eva van Walree, Benjamin M. Jacobs, Teng Hiang Heng, Qin Huang, Ataf Sabir, Saadia Rahman, Saghira Malik Sharif, Ahsan Khan, Maša Umićević Mirkov, Hiroyuki Kuwahara, Xin Gao, Fowzan S. Alkuraya, Daniëlle Posthuma, William G. Newman, Chris Griffiths, Rohini Mathur, David A. van Heel, Sarah Finer, Jared O’Connell, Hilary C. Martin
Abstract
Autozygosity is associated with rare Mendelian disorders and clinically relevant quantitative traits. We investigated associations between the fraction of the genome in runs of homozygosity (F ROH ) and common diseases in Genes & Health (n = 23,978 British South Asians), UK Biobank (n = 397,184), and 23andMe. We show that restricting analysis to offspring of first cousins is an effective way of reducing confounding due to social/environmental correlates of F ROH . Within this group in G&H+UK Biobank, we found experiment-wide significant associations between F ROH and twelve common diseases. We replicated associations with type 2 diabetes (T2D) and post-traumatic stress disorder via within-sibling analysis in 23andMe (median n = 480,282). We estimated that autozygosity due to consanguinity accounts for 5%–18% of T2D cases among British Pakistanis. Our work highlights the possibility of widespread non-additive genetic effects on common diseases and has important implications for global populations with high rates of consanguinity.