APA Dictionary of Psychology

n. an autosomal recessive, lysosomal storage disease caused by mutation of the CTSK gene and characterized by moderately short stature (affected individuals rarely reach an adult height of 5 ft); increased bone density; underdeveloped fingertips with absent or small nails; delays in the closing of skull sutures; an abnormal collarbone (clavicle); and distinctive facial features, including a large head with a small face and chin, underdeveloped facial bones, a high forehead, and dental abnormalities.