A folate sensitive heritable fragile site at 19p13

Abstract
A fragile site at 19p13 was found in the mother of a newborn girl with Downs syndrome. The fragile site was expressed in medium containing low folate and by addition of FdU [fluorodeoxyuridine], whereas high folate, thymidine and thymidine-analogs inhibited the expression. This fragile site may prove valuable for linkage studies on chromosome 19.