从人类学到遗传学的许多研究领域都对人口中的关系推断感兴趣。可以从他们的遗传数据中直接推断一对夫妇中两个个体之间的关系,也可以从他们后代之一的遗传数据中间接推断。出于这个原因,人们可能想知道,抽样夫妇或单身个体来研究人群中夫妇的关系是否更有利。的确,对两个个体进行抽样比对一个个体进行抽样更有意义,因为我们看到的是四种单倍型,而不是两种,但这也使研究成本加倍,是一个更复杂的抽样方案。为了回答这个问题,我们使用真实的人类单倍型对来自10种不同关系的1000个三重奏进行了模拟,以获得真实的全基因组遗传数据。然后,我们比较了使用单点和多点方法从一对个体或其中一个后代获得的基因组共享系数和关系推断。我们观察到,对于比第一表亲更亲密的关系,在关系推断方面,成对的个体比他们的一个后代信息更丰富,从单点方法获得的亲属关系系数给出了更准确或等效的基因组共享估计。对于更多的远程关系,后代对关系推断有更多的信息,从多点方法获得的近交系数给出了更准确的基因组共享估计。总之,对父母对或其后代之一的关系推断提供了补充信息。如果可能,应该鼓励三重奏采样,因为它可以允许跨越更广泛的潜在关系。
Relationship inference in a population is of interest for many areas of research from anthropology to genetics. It is possible to directly infer the relationship between the two individuals in a couple from their genetic data or to indirectly infer it from the genetic data of one of their offspring. For this reason, one can wonder if it is more advantageous to sample couples or single individuals to
study relationships of couples in a population. Indeed, sampling two individuals is more informative than sampling one as we are looking at four haplotypes instead of two, but it also doubles the cost of the
study and is a more complex sampling scheme. To answer this question, we performed simulations of 1000 trios from 10 different relationships using real human haplotypes to have realistic genome-wide genetic data. Then, we compared the genome sharing coefficients and the relationship inference obtained from either a pair of individuals or one of their offspring using both single-point and multi-point approaches. We observed that for relationships closer than 1st cousin, pairs of individuals were more informative than one of their offspring for relationship inference, and kinship coefficients obtained from single-point methods gave more accurate or equivalent genome sharing estimations. For more remote relationships, offspring were more informative for relationship inference, and inbreeding coefficients obtained from multi-point methods gave more accurate genome sharing estimations. In conclusion, relationship inference on a parental pair or on one of their offspring provides complementary information. When possible, sampling trios should be encouraged as it could allow spanning a wider range of potential relationships.