Nail-patella syndrome

[Gregory]

Nail-patella syndrome is a rare hereditary disorder that results in abnormalities of the kidneys, bones, joints, toenails, and fingernails.
Nail-patella syndrome is caused by a mutation of a gene that plays an important role in the development of limbs and kidneys.
Commonly, people who have this syndrome are missing one or both kneecaps (patellas), have an arm bone (radius) that is dislocated at the elbow, and have an abnormally shaped pelvic bone. Their fingernails and toenails are missing or poorly developed, with pitting and ridges.
About 50% of people with this syndrome have blood in their urine (hematuria) or protein in their urine (proteinuria). Kidney failure eventually develops in about 30% of the people with affected kidneys by the time they are 50 or 60. People who have kidney problems often have high blood pressure (hypertension).
(See also Overview of Hereditary Connective Tissue Disorders.)