2003, Karl-Heinz Grzeschik, 66: Greig Cephalopolysyndactyly Syndrome, Mary Ann McLaughlin (supervising editor), NORD Guide to Rare Disorders, National Organization for Rare Disorders, Wolters Kluwer (Lippincott Williams & Wilkins), page 201, Postaxial polydactyly is common in the hands and preaxial polydactyly in the feet.
Source: wiktionary