Nail Patella Syndrome

Nail patella syndrome (NPS) is a rare genetic disorder characterized by abnormalities of the nails, knees, elbows, and pelvis. It is also known as hereditary onycho-osteodysplasia or Fong disease.

Causes and Inheritance

Nail patella syndrome is caused by mutations in the LMX1B gene, which provides instructions for making a protein involved in the development of limbs and other tissues. The condition is inherited in an autosomal dominant pattern, meaning that one copy of the altered gene in each cell is sufficient to cause the disorder.

Symptoms

The symptoms of nail patella syndrome can vary widely among affected individuals, but common features include:

• Abnormalities of the nails, such as:
  • Underdeveloped or absent fingernails and toenails
  • Thin, brittle, or ridged nails
  • Nails that are triangular or V-shaped
• Knee problems, such as:
  • Patellar hypoplasia (underdeveloped kneecap)
  • Patellar dislocation (kneecap out of place)
  • Patellofemoral pain syndrome (pain in the front of the knee)
• Elbow problems, such as:
  • Limited range of motion
  • Pain or stiffness
• Pelvic abnormalities, such as:
  • Hypoplastic (underdeveloped) ilia (the widest and uppermost of the three bones that merge to form the pelvis)
  • Renal problems, such as kidney disease or cysts
• Other possible features:
  • Skeletal abnormalities, such as scoliosis or clubfoot
  • Eye problems, such as glaucoma or cataracts
  • Hearing loss

Diagnosis

Nail patella syndrome is typically diagnosed based on a combination of clinical evaluation, family history, and imaging studies. Diagnostic tests may include:

• X-rays to evaluate the bones and joints
• CT or MRI scans to assess the pelvis and kidneys
• Genetic testing to identify mutations in the LMX1B gene

Treatment and Management

Treatment for nail patella syndrome is usually focused on managing the symptoms and preventing complications. This may include:

• Orthopedic care, such as physical therapy or surgery, to address knee, elbow, or pelvic problems
• Pain management, such as medication or alternative therapies
• Routine monitoring of kidney function and blood pressure
• Regular eye exams to detect potential vision problems
• Hearing tests to assess for hearing loss

Prognosis

The prognosis for individuals with nail patella syndrome varies depending on the severity of the symptoms and the presence of any complications. With proper management, many people with NPS can lead active and fulfilling lives.

Frequently Asked Questions (FAQs)

What is Nail patella syndrome?
A rare genetic disorder characterized by abnormalities in limb development and other physical features.

What are the typical symptoms of Nail patella syndrome?
Symptoms may include nail dysplasia, kneecap dislocation, elbow deformities, and kidney problems.

Is Nail patella syndrome inherited?
Typically inherited in an autosomal dominant pattern, meaning a single copy of the mutated gene is enough to cause the condition.

What are the chances of passing Nail patella syndrome to offspring?
Each child of an affected parent has a 50% chance of inheriting the mutated gene.

Are there any other names for Nail patella syndrome?
Also known as hereditary onycho-osteodysplasia or Fong disease.

Can Nail patella syndrome be diagnosed prenatally?
Possibly through genetic testing, but this is not always available or accurate.

What are the treatment options for Nail patella syndrome?
Treatment typically focuses on managing symptoms and may include surgery, physical therapy, and pain management.

Is there a cure for Nail patella syndrome?
No known cure, but treatment can help alleviate symptoms and improve quality of life.

How common is Nail patella syndrome?
A rare condition, estimated to affect approximately 1 in 50,000 people.

What are the potential complications of Nail patella syndrome?
May include kidney disease, eye problems, and increased risk of fractures due to bone abnormalities.