multifactorial /-faktôr″ē·əl/ [L, multus, many, facere, to make] , pertaining to or characteristic of any condition or disease resulting from the interaction of many factors, specifically the interaction of several genes, usually polygenes, with or without the involvement of environmental factors. Many disorders, such as spina bifida, neural tube defects, and Hirschsprung’s disease, are considered to be multifactorial.
