Stacy Brookhyser, who is gene-positive for Huntington's disease and the mother of twins, spoke about preimplantation genetic diagnosis (PGD) for families seeking to have HD-free children. Stacy started the website HDFreeWithPGD.com. She spoke at the annual convention of the Northern California Chapter of the Huntington's Disease Society of America (HDSA) on May 7, 2011, in Sacramento, CA.