ApoE4 is a gene that is prevalent in European populations.  Changes in it have been associated with the development of dementia. Those that are homozygous for the faulty gene ( carry 2 copies)   seem to be at an increased risk of developing severe Covid19.

It does not matter if they had dementia or not, it was the genes that mattered.

Interesting because this study suggests that high risk of death in care homes may not be simply due to advancing age and frailty  i.e. They say it could be due to this underlying genetic change which puts people at risk for both Covid-19 complications and dementia.

Hz

https://www.itv.com/news/westcountry/2020-05-26/faulty-gene-linked-to-dementia-could-double-risk-of-severe-coronavirus-reveals-exeter-led-study/

It is interesting.  2 weeks ago UK started quite an interesting study to compare genomes of those in ICU with those with mild disease.

  A lot more genes may be found.  This shouldn't just tells us about who is susceptible but also give us valuable insight into the molecular mechanisms by which this  virus causes disease.

The sample size will be quite big because unfortunately we have been hammered over here.  

Hz x

Genetics

Thousands of UK patients who have fallen ill with coronavirus will have their genomes read in a major study to understand how a person’s DNA affects their susceptibility to the infection.

The nationwide effort aims to collect DNA samples from up to 20,000 Covid-19 patients currently or previously in intensive care units, along with 15,000 more from patients who had mild or moderate symptoms.

https://www.theguardian.com/science/2020/may/13/coronavirus-patient-dna-study-could-tell-us-why-some-fare-worse