Eye Diseases Linked to Genetic Defects

Scientists have linked two eye diseases to genetic defects in the powerhouses of cells, providing further evidence that damage to such genetic material may cause a variety of illnesses. Emory University researchers in Atlanta reported that they had confirmed that a previously identified flaw in the mitochondrial DNA of cells is to blame for Leber’s hereditary optic neuropathy, a rare inherited disease that causes blindness.

In the same issue of the New England Journal of Medicine, another scientific team last week linked damage to the same kind of genetic material to a disorder called progressive external ophthalmoplegia, which weakens eye muscles.

Douglas Wallace, a biochemistry professor who headed the Emory team, said the studies--coupled with his previous research on a form of epilepsy--show such genetic damage may be involved in far more diseases than previously thought.

Every cell contains mitochondria, which are microscopic, energy-producing bodies. The genetic material contained in the tiny powerhouses is called mitochondrial deoxyribonucleic acid (DNA), and unlike other types of DNA, it is inherited only from women.