What is Retinitis Pigmentosa?


An inherited disease that can lead to blindness affects more than 100,000 people in the United States, including some celebrities such as Stephen A. Wynn, Jon Wellner, Woody Shaw and Isaac Lidsky. Even though the disease affects so many people, most are unaware what causes the disease, what treatments are available and how to recognize the symptoms.

What is Retinitis Pigmentosa?

Retinitis Pigmentosa, often called RP, affects the retina which lies in the back of the eye. Photoreceptor cells known as rods and cones die in the retina of someone with RP, causing a gradual decline in vision. In most people with RP, a gene mutation is inherited from one or both parents that tell the photoreceptor cells to either make too much or too little protein. Improper levels of protein cause cells to function improperly.

Inheritance Factors

There are three genetic inheritance patterns that can cause RP. When both parents carry one copy of a mutated gene but do not have symptoms, it is known as autosomal recessive RP and children have a 25 percent chance of developing the disease. When one parent is affected and is the only parent with the mutated gene, it is known as autosomal dominant RP and children have a 50 percent chance of contracting the disease. In X-linked RP, sons of the mother who carries the disease have a 50 percent chance of being affected. Daughters are not usually affected and, if they are, the symptoms are usually mild, although they do carry the gene.

Symptoms of RP

Symptoms of RP can vary depending on whether the rods or cones are involved. Because rods are often affected first, the initial symptom of RP may be changes in peripheral and night vision. When centrally located cones become involved, color perception and central vision can be affected. The disease is usually diagnosed when people are in their teens or as young adults. Most people who are diagnosed with RP are legally blind by age 40.

Available Treatments

Because RP is caused by different mutant genes, treatments for the disease are different depending on the type diagnosed. Gene therapy is showing promise in children and young adults who have a severe form of the disease known as Leber congenital amaurosis (LCA). Several patients have had their vision restored during clinical trials of the treatment. Valproic acid has shown promise in treating autosomal dominant forms of RP in clinical trials. Dietary supplements that include Vitamin A palmitate and consumption of oily fish high in Omega-3 fatty acids have been shown to slow the vision loss of patients with the disease. Other gene therapies have shown promise in restoring the function of cones long after they have stopped working due to RP. Recently, funding was provided to continue research into three compounds that appear to boost mitochondrial function and slowing vision loss in patients with RP.

Genetic testing is available for those who suspect they have the disorder. It is also recommended that when one family member is diagnosed that all family members be genetically tested as early diagnosis can help preserve vision longer.

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