Two thoughts:
First maybe there's a relationship with those who suffer from aplastic anemia, the other bad adaptation to malaria, and maybe there's a relationship to malaria itself. The latter could mean we will have to develop a maintenance solution. The first could mean there is a genetic relationship we need to consider.
It's good that people are looking at such as genetic links. However I think the sociological explanations seema more appropriate since they reflect the results sociological material consequences one might expect, availability of medical support, need for resources to survive, etc.
The sociological explanation is the one people want. The Occam’s razor explanation is the one you don’t say in public.
The sociological explanation is the one Occam's razor favours. There
may be genetic factors that cause black people to suffer more severe cases on average, all else equal, or their
may be none, or there may even be genetic factors that would cause white people to suffer (slightly) more severe cases on average, all else equal, but with the effects swamped by other factors. There is no way to tell just from the raw death rates because all else isn't equal.
We do however know that black people in the US tend to be poorer, have less insurance coverage, are concentrated in urban areas where they are reliant on public transport, are more often employed in jobs that do not accomodate working from home, and live in larger households than white people. Those
known factors alone predict higher rates for blacks (and Latinos).
If you want to make the case that a not directly demonstrated genetic factor also plays an important role, you have to do one of two things:
- directly demonstrate it, e.g. identify genetic variants that are reliably correlated with severe outcomes and that are more common among blacks, and quantify their contribution to the racial disparity in outcomes, or
- positively show that the upper bound for the expected effect size of the known (sociological) factors is insufficient to explain the observed disparity in outcomes.