Who has which rare disease? A map of 406 rare diseases across ethnic groups in England
Of 62.5 million people in England, 1.7% had one of 406 rare diseases, and they had more recorded COVID-19 infection (32.8% vs 29.0%).
The question
Rare diseases are individually uncommon, but together they affect a lot of people. We know that COVID-19 hit people with rare diseases especially hard. What we did not know is how that burden differs between ethnic groups, because we did not have a clear picture of who has which rare disease in the first place.
What we did
Working with linked NHS England records covering 62.5 million people alive on 31 July 2023, we counted how common 406 rare diseases are within different, finely defined ethnic groups. We then looked at how much COVID-19 infection each of these groups of patients carried.
What we found
About 1.05 million people (1.7%) had at least one of the 406 rare diseases. Recorded COVID-19 infection was higher among them than in the wider population (32.8% against 29.0%). Rare diseases are not spread evenly across ethnic groups, and the pattern of COVID-19 risk by ethnicity among people with rare diseases is complicated. It often runs against the trends seen in the general population. Using the detailed ethnicity categories NHS records use revealed differences that broad categories hide. This is likely because the underlying differences in which rare diseases are common in which groups run deep.
Why it matters
A map like this shows which combinations of rare disease and ethnic group face the greatest overlapping risk. That helps health services decide where to look first, and it gives researchers a foundation for explaining why those gaps exist.