A health condition that affects the child’s nail and bone development is called nail-patella syndrome. In most cases, this condition impacts the size and shape of the fingernails, kneecaps, and elbows. In rare cases, people with nail-patella syndrome may also develop glaucoma or kidney disease. The treatment goal is to relieve the symptoms, prevent serious complications, and improve your quality of life.
While knowing your child has a genetic disorder can make you scared or anxious, you should express your concerns to the child’s healthcare professional. However, most children and adults with nail-patella syndrome have a normal lifespan.
Symptoms
This syndrome can make some parts of the body look or function differently. Check below for the most common symptoms of nail-patellar syndrome:
- Nails – The nails may be small or missing. They can also have ridges, pits, or discoloration. This syndrome mostly affects fingernails more than toenails. The most severe changes are often in the thumbs and index fingers.
- Kneecap (patella) – While kneecaps can be small, they can also be differently shaped or even missing. Usually, in children with nail-patellar syndrome, the kneecaps are located higher up and farther to the side than in children without this disorder. They may also experience pain and may feel unstable.
- Elbow – This syndrome may also affect the development of the arms. They may also have extra skin (webbing) that extends across the elbow area. As a result, it affects the ability to twist and extend the arms.
- Pelvis – In children with this syndrome, there may be some small bony structures that extend from the pelvic bone. These small structures are called iliac horns. Usually, they appear only on one side of the child’s pelvis. While you can feel them through the skin, they often do not cause any problems.
- Eyes – Sometimes, the condition may negatively affect the child’s eyes and cause ocular hypertension (high blood pressure). Without treatment, this condition may progress to glaucoma and cause blurred vision, headaches, and other symptoms.
- Kidneys – Approximately 40% of people with this syndrome develop kidney disease. This condition often ranges from mild to life-threatening.
Sometimes, people with this genetic disorder may have other symptoms. For example:
- Reduced bone mineral density
- Numbness, tingling, or burning in the hands and feet
- Weak or crumbling teeth or thin enamel
- Scoliosis (abnormal curvature of the spine)
- Constipation
- Reduced muscle mass in the arms and legs
- Tight Achilles tendon
- Irritable bowel syndrome
Causes
This condition occurs due to mutations (changes) in certain genes. In most cases, people with nail-patellar syndrome have changes to their LMX1B gene. It is responsible for producing a protein (LMX1B protein) that helps the arms, legs, eyes, and kidneys to develop during pregnancy. In people with nail-patellar syndrome, this gene works differently, which leads to abnormalities.
Sometimes, people have symptoms of this syndrome without having mutations in their LMX1B gene. However, it is very rare. Moreover, the research is ongoing to look for more clues because experts believe other genes may also play a role.
How is Nail-Patella Syndrome Inherited?
The abnormal gene often passes from one generation to the next in an autosomal dominant pattern. Moreover, it is enough for just one copy of the abnormal gene to develop this condition. There is a 50% chance of passing the abnormal gene to your children in the future. While the risk stays the same for each pregnancy, it is also the same no matter your sex.
About 9 in 10 people with this syndrome have a family history of the disease. It means you have a parent who carries the abnormal gene or has this condition. However, about 10% of people with this condition do not have a family history of the disease. In such cases, these children are the first in their families with this genetic disorder.
What Are The Possible Complications of Nail-Patellar Syndrome?
People with this syndrome may also experience some complications, especially if they do not treat it. Check some of them below:
- Vision loss (often caused by untreated glaucoma)
- Kidney failure
- Osteoarthritis in the kneecaps or elbows
- An increased risk of preeclampsia during pregnancy
- Progressive nephropathy
- Lester’s sign
- Neuropathic pain
People who develop serious kidney disease may need dialysis or a kidney transplant to treat the condition. This article does not contain a full list of nail-patellar syndrome complications. In any case, you can consult with your doctor about ways to reduce the risk or even prevent the previous complications.
How to Prevent Nail-Patellar Syndrome?
Unfortunately, it is not possible to prevent a genetic condition. However, if you plan to become pregnant, it is recommended to perform genetic tests to make sure you do not have this abnormal gene, especially if you have a family history of the disease. It is essential to understand the risks of having children with nail-patellar syndrome.
Diagnosis
The diagnosis often begins with a physical examination to check for abnormalities linked to the disease. Doctors may also ask some questions about the symptoms and family history to get more clues about the disease. Sometimes, it is difficult to diagnose this condition because the symptoms resemble other health conditions. Check below some tests often done to confirm or rule out this condition:
- Imaging tests – The following tests allow doctors to examine the bones more closely. For example, X-rays, CT (computed tomography) scans, and MRI (magnetic resonance imaging) scans.
- Blood and urine tests – These tests are often done to determine how well the kidneys are working.
- Kidney biopsy – If your doctor suspects a kidney condition, they may take a small sample of the kidney for testing.
- Genetic tests – These tests require a blood sample that is sent to the laboratory. The technicians are checking for the abnormal gene often present in people with nail-patellar syndrome.
Treatment
This is a chronic (long-term) health condition that requires treatment for the rest of your life. It cannot be cured. That’s why the treatment goal is to ease the symptoms and prevent life-threatening complications. Check below some treatment options often prescribed by doctors for people with this genetic disease:
- Physical therapy – During this therapy, doctors will teach you exercises that will help improve mobility.
- Medicines – Doctors often prescribe different medications to relieve musculoskeletal pain, manage blood pressure, and pressure in the eyes.
- Surgery – In more severe cases, physicians recommend surgery to fix bone abnormalities, treat glaucoma, and severe kidney disease (including kidney transplantation).
Frequently Asked Questions
Which providers will diagnose and treat my child?
Usually, children with this genetic condition need several providers to treat the symptoms of nail-patella syndrome. These include:
- Orthopedists – Healthcare professionals specialized in treating bone problems.
- Nephrologists – These healthcare professionals specialize in treating kidney disease.
- Ophthalmologists – Eye care specialists
When should my child see a healthcare provider?
If you notice your child experiences any of the symptoms of nail-patellar syndrome, immediately contact your healthcare professional. Usually, children with nail-patellar syndrome need routine:
- Glaucoma screenings
- Bone density tests
- Urine tests (including those that measure albumin-creatinine levels)
- Blood pressure checks
How rare is nail-patella syndrome?
This is a rare genetic disorder that affects about 1 in every 50,000 people, according to some research. However, this condition can be more common because people with mild forms of the disease go undiagnosed. Ask your healthcare provider if you have any other questions.
