Aug 9, 2013

When a Condition is More than a Retinal Disease

Science Education

The Foundation Fighting Blindness is, of course, all about finding treatments and cures for retinal degenerative diseases. However, we are well aware that many of our constituents and their families are dealing with more than just vision loss. That’s because genetic defects causing retinal conditions can sometimes affect other parts of the body. The result is conditions often referred to as syndromes.

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Image of photoreceptors

The Foundation Fighting Blindness is, of course, all about finding treatments and cures for retinal degenerative diseases. However, we are well aware that many of our constituents and their families are dealing with more than just vision loss. That's because genetic defects causing retinal conditions can sometimes affect other parts of the body. The result is conditions often referred to as syndromes.

For example, gene mutations that lead to Usher syndrome not only cause retinitis pigmentosa (RP), they affect the inner ear, leading to deafness, and sometimes, balance problems.

Bardet-Biedl syndrome is characterized by a number of conditions including: RP, obesity, and problems with brain development, liver function, the cardiovascular system and a number of other body systems.

Leber congenital amaurosis is best known as a severe form of RP, but some people with the disease have kidney problems, as well.

Many of these syndromes have a common link — they affect the function and health of cilia, slender tube-like structures that are extensions of different types of cells. Cilia are organelles — organs within organs — that provide sensory functions, clear waste and debris, and play important roles in cellular development and damage repair. Photoreceptors, the cells in the retina that enable us to see, have protrusions which are sensory cilia. When a condition affects cilia, it's called a ciliopathy.

While the Foundation only funds research for the retina, what we learn about retina-related ciliopathies may have an impact on understanding and treating other affected organs and systems. When scientists find the genetic defect causing the retinal disease — and figure out how the defect impacts the health and well-being of photoreceptors — the knowledge can be applied to understanding and treating other affected cilia in the body.

For people and families affected by syndromic conditions, good medical care from multiple specialists is critical to managing the different issues. Jacque Duncan, M.D., a clinical researcher from the University of California, San Francisco, says that genetic specialists are the best experts for evaluating and diagnosing people with these conditions. "They know all about the different organs and systems that are affected by the different genetic mutations," she says.

Dr. Duncan also recommends that families seek genetic counseling. "It's very important for families affected by syndromic conditions to talk with a genetic counselor, so they have a good idea of the risk to different family members," says Dr. Duncan. "Genetic counseling, in combination with a consultation with a physician specializing in genetics, can also help determine whether genetic testing is available and if it might be beneficial."

The Foundation has genetic counseling and testing information available online for both patients and doctors. In addition, we can provide the names of retinal specialists who are interested in treating people with inherited retinal diseases. Call 800-683-5555 or e-mail us at info@FightBlindess.org for more information.