Nail Patella Syndrome (NPS), also known as Hereditary Onychoosteodysplasia or Fong syndrome, is a rare genetic disorder that primarily affects the development of nails, kneecaps, elbows, and kidneys. It is an autosomal dominant condition, meaning that a person inherits the disorder if they receive the defective gene from either parent.
Individuals with Nail Patella Syndrome typically exhibit nail abnormalities, such as small, underdeveloped, or absent fingernails and toenails. The condition can also cause malformation or absence of the kneecaps, resulting in knee instability and joint pain. Elbow abnormalities, including limited extension or elbow joint dislocations, may also occur in individuals with NPS.
Furthermore, Nail Patella Syndrome can lead to kidney dysfunctions, specifically affecting the ability to filter waste products from the blood, resulting in proteinuria (the presence of excess protein in the urine) and impaired kidney function. This may eventually progress to kidney failure or kidney disease.
Other associated features of NPS may include skeletal abnormalities like abnormal bone development or progressive scoliosis (sideways curvature of the spine), eye abnormalities such as glaucoma or cataracts, and hearing loss.
The severity and range of symptoms can vary widely, even among affected individuals within the same family. Therefore, the diagnosis of Nail Patella Syndrome is primarily based on the presence of specific physical features and a thorough evaluation of family history, supplemented by genetic testing to confirm the presence of mutations in the LMX1B gene.
While there is currently no cure for Nail Patella Syndrome, treatment options focus on managing the symptoms and associated complications, typically involving a multidisciplinary approach where healthcare professionals from various specialties collaborate to address the specific needs of affected individuals.
