More than 1000 genes may contribute to a person's risk of developing severe covid-19, on top of life circumstances such as their age, ethnicity and any health conditions. Most of the genes, discovered in a study of more than 1 million people, affect the functioning of two kinds of immune cells. If the results are confirmed, they could inform a test that assesses a person's risk of getting badly ill with covid-19, says Johnathan Cooper-Knock at the University of Sheffield, UK. "We know there are young people who are otherwise fit that get severe covid," he says. "We are trying to get at the genetic determinants that put people at risk irrespective of the more obvious things." Cooper-Knock's team used artificial intelligence to analyse results from a global dataset called The Covid-19 Host Genetics Initiative, a genetics project run by a group of researchers and companies.

A machine-learning algorithm has helped scientists find 690 human genes associated with a higher risk of developing motor neuron disease, according to research published in Cell this week. Neuronal cells in the central nervous system and brain break down and die in people with motor neuron disease, like amyotrophic lateral sclerosis (ALS) more commonly known as Lou Gehrig's disease, named after the baseball player who developed it. They lose control over their bodies, and as the disease progresses patients become completely paralyzed. There is currently no verified cure for ALS. Motor neuron disease typically affects people in old age and its causes are unknown.