Peter Attia· MD
prader-willi is a genetic disorder in which rather than having a single gene affected there is a region of the which is in most instances not all but the majority of instances deleted so there's a region of chromosome 15 in which there is a large deletion that is a region that has normally 20 or so genes in it and when deleted when the paternal the father's copy of this interval is deleted the individual becomes has a very characteristic phenotype