Self-reported ethnicity was an imperfect indicator of genetic ancestry, with 9% of individuals having >50% genetic ancestry from a lineage inconsistent with self-reported ethnicity. Limitations of self-reported ethnicity led to missed carriers in at-risk populations: for 10 ECS conditions, patients with intermediate genetic ancestry backgrounds—who did not self-report the associated ethnicity—had significantly elevated carrier risk. Finally, for 7 of the 16 conditions included in current screening guidelines, most carriers were not from the population the guideline aimed to serve.
It’s long been known that a certain percentage of people for various reasons give an ethnic background that doesn’t match their total genome. This is a problem because of the frequency of carriers varies by population. I first began to be curious about this issue 15 years ago. Today there is no excuse in my opinion for not genotyping if you are a hospital.
The wholesale costs of SNP-arrays are $25, and there are pretty simple turn-key ancestry inference algorithms. This doesn’t need to be an issue. This is 2020.