Nail patella syndrome (NPS) is a genetic disorder that results in small, poorly developed nails and kneecaps, but can also affect many other areas of the body, such as the elbows, chest, and hips. The name “nail-patella” can be very misleading because the syndrome often affects many other areas of the body, including even the production of certain proteins.:666 It is also referred to as iliac horn syndrome, hereditary onychoostedysplasia, Fong disease or Turner Kiser syndrome. The hallmark features of this syndrome are poorly developed fingernails, toenails, and patellae (kneecaps). Sometimes, this disease causes the affected person to have either no thumbnails or a small piece of a thumbnail on the edge of the thumb. Other common abnormalities include elbow deformities, abnormally shaped pelvic (hip) bones, and kidney (renal) disease. Also, some research shows people with NPS are more prone to glaucoma and scoliosis, due to poorly developed spines. People with nail-patella syndrome may display only a few or many of the recognized signs of this disease. Symptoms vary widely from person to person. Signs even vary within a single family with multiple affected members.