Figure 3.

First 92K Sequenced Individuals from the DiscovEHR Cohort Contain an Extensive Amount of Relatedness

(A) A plot of IBD0 versus IBD1 shows pairwise relationships segregating into different familial relationship classes. The IBD sharing distributions of second- and third-degree relationships overlap with each other, so a hard cutoff halfway between the two expected means was selected. Third-degree relationships are challenging to accurately estimate because of the technical limitations of exome data as well as the widening and overlapping variation around the expected mean IBD proportions of more distant relationship classes (e.g., fourth degree and fifth degree). We provided a lower-bound estimate of the number of third-degree relationships.

(B) The distribution of size of first-degree family networks ranges between 2 and 34 sequenced individuals, and the vast majority are smaller family networks.

(C) The largest reconsturcted first-degree family network consisting of 34 sequenced individuals; more than 99.98% of the first-degree family networks’ pedigree structures were reconstructed from the genetic data.

(D) The largest second-degree family network, consisting of 19,968 individuals (∼22% of the dataset), shows 4,062 first-degree family networks (represented as red boxes that are proportionally sized to the number of individuals in the network, including the network corresponding to the pedigree shown in [C]), and 5,584 additional individuals (black nodes) connected by 11,430 second-degree relationships (blue edges).