birth defect A structural, functional, or metabolic abnormality present at birth that results in physical or mental disability or is fatal. There are more than 4,000 known birth defects, which may be caused by genetic or environmental factors. About 150,000 babies are born each year with birth defects. Related category • GENETICS AND HEREDITY Source: National Human Genome Research Institute Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |