Nail-patella syndrome (also called osteo-onychodysplasia, arthro-onychodysplasia, and onycho-osteodysplasia) is a rare hereditary disorder that results in abnormalities of the kidneys, bones, joints, and fingernails.

The gene that causes nail-patella syndrome is dominant. Commonly, people who have this syndrome have one or both kneecaps (patellas) missing, one of the arm bones (the radius) dislocated at the elbow, and the pelvic bone abnormally shaped. They have either no fingernails or poorly developed ones, with pitting and ridges. About 30% to 40% of people with this syndrome have blood or protein in their urine, which may prompt the doctor to order kidney function tests. Kidney failure eventually develops in about 30% of the people with affected kidneys by the time they are 50 or 60. The diagnosis is confirmed by bone x-rays and a biopsy of kidney tissue.

There is no effective treatment for this syndrome. Controlling blood pressure may slow the rate that kidney function deteriorates. Those who develop kidney failure need dialysis or a kidney transplant. Genetic testing is usually offered to people who want to have children.

Last full review/revision February 2008 by Frank Pessler, MD, PhD; David D. Sherry, MD