Norrie Disease

Norrie disease is a rare X-linked recessive genetic disease that causes congenital blindness and hearing loss. Babies who have it are born blind or lose their vision by the time they’re a few months old. Your baby may also develop hearing loss as they grow up. Males are more likely to have this disease, too.

The condition occurs when a genetic change happens during fetal development. The change affects how the fetus’s retina and inner ear develop. The combination of hearing and vision loss often leads to developmental delays, behavioral issues and intellectual disabilities.

Symptoms of Norrie disease

Blindness at birth or soon after birth is the most common symptom of Norrie disease. Other symptoms include:

• Hearing loss: The condition may affect inner ear development. Hearing loss may start in early childhood and get worse as your child grows up.
• Behavioral changes: Norrie disease may impact your child’s behavior. For example, 1 in 4 people with Norrie disease have a neurological disorder that causes them to laugh or cry uncontrollably (pseudobulbar affect).
• Developmental delays: Symptoms may include delays in rolling over and sitting up, as well as issues with fine motor skills.
• Intellectual disabilities: Your child may have issues with learning, reasoning and everyday life skills.

Norrie disease causes

Norrie disease happens when the NDP gene changes. The change affects the norrin protein that helps retinas develop. The genetic change also affects the development of blood vessels that supply blood to your retina and inner ear. The change can lead to several eye disorders known as NDP-related retinopathies.

How is this disorder inherited?

People inherit this Norrie disease through an X-linked recessive inheritance pattern. This genetic change means only one change on the X chromosome needs to pass from one biological parent to their male child for that child to inherit the change.

Risk factors

A family medical history of Norrie disease increases the risk that your child will inherit the genetic change that causes it. If someone in your family has this disorder, you may want to talk with a genetic counselor to learn more about your risk of having the disease or passing the genetic change on to a child.

Complications

People with Norrie disease may have certain conditions associated with the genetic change that leads to Norrie disease. Those conditions include:

• Autism: About 1 in 4 people with Norrie disease also have autism or autism-like symptoms.
• Peripheral vascular disease: Some people with Norrie disease develop venous ulcers or other problems related to blood circulation.
• Seizures: Though less common than other features, seizures may affect about 1 in 10 people with Norrie disease.

How doctors diagnose this disorder

An ophthalmologist will do an eye exam. They’ll look for signs of Norrie disease, like retinal detachment or if your child’s pupils look white. They’ll ask if any family member has Norrie disease. They may do genetic tests to look for the genetic change that causes the disease.

How is Norrie disease treated?

There isn’t a treatment to restore your child’s vision. Their ophthalmologist may recommend laser and/or specific surgeries to ease eye pain or manage conditions like retinal detachments and cataracts. If your child has hearing loss, they may benefit by:

• Wearing hearing aids
• Having cochlear implants
• Receiving speech therapy

Your child may also benefit from educational support services. It’s important to talk to administrators at your child’s school to learn what resources are available.

When should I seek care?

Some babies with Norrie disease have vision loss within the first few months of life. And they may develop hearing loss as they grow up. You should talk to your child’s pediatrician if you notice changes in your child, like:

• Difficulty following moving objects or people with their eyes
• Tilting or turning their head when they look at things close up
• Not reacting to changes in light, movement or sound

What is the prognosis for Norrie disease?

Your child and you will face lifelong challenges. Those challenges will vary depending on how Norrie disease affects your child. Your child’s team of healthcare providers is your best resource of information about ways the condition may affect your child. But in general, they’ll have regular check-ups, including:

• Eye exams: Your child should have annual eye exams even if they don’t have vision. Their ophthalmologist will check for issues like eye pain or cataracts.
• Hearing tests: Your child should see an audiologist every six to 12 months. Their audiologist will do hearing tests to check your child’s hearing.
• Well-child check-ups: Your child will need routine visits with a pediatrician to monitor their overall health.

How can I help my child?

Your child may need help with managing daily life. Children with Norrie disease may have trouble going to sleep and staying asleep. Ask your child’s pediatrician for help if your child isn’t getting enough rest.

How do I take care of myself and my family?

You need to take care of yourself so you can take care of your child. That may be easier said than done. You may feel like there aren’t enough hours in the day. Here are some suggestions that may help:

• Don’t go it alone. Members of your extended family, your friends and others may be able to take care of daily tasks so you can focus on your child and family.
• Find support. Check out support groups for families and others who care for children who have needs like your child’s. It may help to connect with others who can relate to your situation.
• Pay attention to your health. Talk to your healthcare provider if you’re coping with exhaustion or mental health issues like anxiety and depression. They’ll suggest treatments or strategies that can help.