Macular Degeneration's Gene Variant

Macular Degeneration's Gene Variant

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly and is known to be hereditary. The disease involves a loss of central vision that makes reading, driving, and recognizing faces increasingly difficult. But because ita multigenic disease—meaning it is caused by multiple genes that may interact in a number of unknown combinations—it’s difficult to study.

A team of University of Michigan scientists is changing that, though. Following reports a year ago on a gene variant strongly linked to AMD, a team led by SPH biostatistician Goncalo Abecasis and Anand Swaroop of the Kellogg Eye Center has identified 20 variants of the same gene that show an even stronger association with the disease.

In the September issue of Nature Genetics, they reported that the non-coding DNA around the gene, Complement Factor H (CFH), may in fact be the primary source of the trouble.

None of the variants studied seemed to account for macular degeneration by itself. Instead, the variants seemed to make multiple, distinct contributions. “There’s probably more than one way to get to macular degeneration,” says Abecasis. AMD is one of the few multigenic disorders for which a set of susceptibility genes has been identified.

Their research has changed the way scientists are thinking, Abecasis says. “It comes out to be a much more complicated picture genetically. Macular degeneration has become the model system for studying multigenic diseases.”

Excitement over the discovery of CFH has led some to begin talking about therapeutic approaches for AMD, but it’s still a bit early, says Swaroop. “Within the next year, we should have a much better idea of how CFH and several other AMD genes together cause the disease.”

UM News Service

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