Department of Anthropology, University of California, Davis, California, USA.
School of Medicine, University of Namibia, Windhoek, Namibia.
Am J Biol Anthropol. 2023 Jan;180(1):207-215. doi: 10.1002/ajpa.24660. Epub 2022 Nov 20.
Height is a complex, highly heritable polygenic trait subject to both genetic composition and environmental influences. Recent studies suggest that a large proportion of height heritability is determined by the cumulative effect of many low allele frequency variants across the genome. Previous research has also identified an inverse relationship between height and runs of homozygosity (ROH); however, this has yet to be examined within African populations. We aim to identify this association within the Himba, an endogamous Namibian population who are recently bottlenecked, resulting in elevated haplotype sharing and increased homozygosity.
Here, we calculate the fraction of the genome composed of long runs of homozygosity (F) in a sample of 245 adults and use mixed effects models to assess its effect on height.
We find that Himba adults exhibit increased homozygosity. However, in contrast to previous studies in other populations, we do not find a significant effect of F on height within the Himba. We further estimated heritability of height, noting both an enrichment of distant relatives and greater developmental homogeneity across households; we find that (SE ± 0.146), comparable to estimates reported in Europeans.
Our results may be due to other environmental variables we were not able to include, measurement error, or low statistical power, but may also imply that phenotypic expression resulting from increased homozygosity may vary from population to population.
身高是一种复杂的、高度遗传的多基因特征，受遗传组成和环境影响。最近的研究表明，身高的大部分遗传率是由基因组中许多低频等位基因变异的累积效应决定的。先前的研究还发现身高与纯合子区域（ROH）之间存在反比关系；然而，这在非洲人群中尚未得到检验。我们旨在在内格罗河人（Himba）中确定这种关联，内格罗河人是一个最近经历瓶颈效应的纳米比亚内婚群体，导致高单倍型共享和杂合子增加。
在这里，我们计算了 245 名成年人样本中由长段纯合子组成的基因组部分（F），并使用混合效应模型评估其对身高的影响。
我们发现 Himba 成年人表现出增加的纯合性。然而，与其他人群的先前研究相反，我们在 Himba 人群中没有发现 F 对身高的显著影响。我们进一步估计了身高的遗传力，注意到远亲的富集和家庭间更大的发育同质性；我们发现，（SE±0.146），与欧洲人报告的估计值相当。
我们的结果可能是由于我们无法纳入的其他环境变量、测量误差或低统计能力，但也可能意味着由于纯合子增加而导致的表型表达可能因人群而异。
