The X-inactivation imprinting model of the fragile-X syndrome: annotated references, 1990.

The X-inactivation imprinting model of the fragile-X syndrome (1), the inference from this model and from pedigree data that human oogonia are derived from two progenitor cells present after the initial event that leads to chromosome imprinting (13), and the general model of fragile sites (8), provide a theoretical framework that is consistent with data on the fragile-X syndrome. This framework has led to novel predictions, some of which have been tested. Results of most tests have been consistent with predictions (10, 13, 17, 18, 27, 28). More direct tests are necessary to explore the underlying mechanisms of chromosome change, here termed imprinting, of the molecular basis of the change, and of the mutation itself.