Nail Patella Syndrome

            Nail Patella Syndrome is categorized as an autosomal dominant disorder. An autosomal dominant disease only requires one parent to carry the gene in order to pass it to the offspring. Offspring of parents with autosomal dominant diseases have a fifty percent chance of having the disease and most likely passing the gene to its offspring. Nail Patella Syndrome occurs on the long arm of Chromosome 9, and is caused by a mutation of the LMX1B gene. It is a genetic, connective tissue disorder that causes small, poorly developed nails and kneecaps, but also affects other parts of the body. .
             Some people with Nail Patella Syndrome have one or both knee caps missing, arm bones may be dislocated at the elbow and the pelvic bone may be abnormally shaped. Many patients with Nail Patella usually live a long life, but some patients succumb to kidney failure, or become confined to a wheelchair. .
             Nail-patella syndrome is characterized by deformities in the nails, knees, elbows and pelvis. The severity of nail-patella syndrome is different in each affected individual. Even members of the same family who are affected with nail patella will display different symptoms. Deformities in nails are the most common defect in nail-patella syndrome. The nails may be absent or poorly developed with ridges and pits, as well as discoloration of the nail. Fingernails are most commonly affected, with the thumbnail being more severely affected than any other nail. The base of the fingernails may also be malformed, having the shape of a triangle instead of the normal crescent shape. .
             People with nail-patella syndrome also tend to have skeletal abnormalities. The knee caps are both very small and irregularly shaped, or the kneecap may be missing altogether. Many people with this disease are also unable to extend their arms at the elbow. Iliac horns, which are unusual bony projections on the iliac bones of the pelvis, are also common among people with nail-patella syndrome.