Long runs of homozygosity (ROH) arise when identical haplotypes are inherited from each parent and thus a long tract of genotypes is homozygous. Cousin marriage or inbreeding gives rise to such autozygosity; however, genome-wide data reveal that ROH are universally common in human genomes even among outbred individuals. The number and length of ROH reflect individual demographic history, while the homozygosity burden can be used to investigate the genetic architecture of complex disease. We discuss how to identify ROH in genome-wide microarray and sequence data, their distribution in human populations and their application to the understanding of inbreeding depression and disease risk.

当从每个亲本继承相同的单倍型时，就会出现长期纯合性 (ROH)，因此一长串基因型是纯合的。表亲结婚或近亲繁殖会产生这种自合子；然而，全基因组数据显示，ROH 在人类基因组中普遍存在，即使在远交个体中也是如此。ROH 的数量和长度反映了个体人口历史，而纯合子负担可用于研究复杂疾病的遗传结构。我们讨论了如何在全基因组微阵列和序列数据中识别 ROH、它们在人群中的分布以及它们在理解近交抑郁症和疾病风险中的应用。