To address this question, we recruited FD patients and healthy, cohabitating relatives to help control for lifestyle factors known to influence comparisons21, such as environment (cohabitants share a built environment), diet (cohabitants are more likely to eat the same food), and genetics (parents carry one copy of the deleterious ELP1 allele and siblings have a 50% chance of carrying the mutant allele). This evidence concerns the gene ELP1 and Fabry disease.