Section 11. Kidney and Urinary Tract Disorders

Chapter 146. Tubular and Cystic Kidney Disorders

Topics: Introduction | Renal Tubular Acidosis | Renal Glucosuria | Nephrogenic Diabetes Insipidus | Cystinuria | Fanconi's Syndrome | Hypophosphatemic Rickets | Hartnup Disease | Bartter's Syndrome | Liddle's Syndrome | Polycystic Kidney Disease | Medullary Cystic Disease | Medullary Sponge Kidney | Alport's Syndrome | Nail-Patella Syndrome

Nail-Patella Syndrome

The nail-patella syndrome 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. The irises of the eyes may be variably colored.

High blood pressure may develop. The urine may contain proteins, usually in small amounts, and rarely blood, which may prompt the doctor to order kidney function tests. Kidney failure eventually develops in about 30% of the people with affected kidneys. 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 of deterioration of kidney function. Those who develop kidney failure need dialysis or a kidney transplant. Genetic testing is usually offered to people who want to have children.