SCIENCE / MEDICINE : Search Narrows for Gene Causing Muscle Atrophy

Scientists reported last week that they have tracked down a genetic defect underlying an inherited muscle disease that strikes thousands of children worldwide. After a three-year search, a research team from Boston and New York said it has located the approximate site of the gene responsible for chronic spinal muscular atrophy. The finding paves the way for therapies for the now untreatable disease, which causes progressive weakness and wasting of muscles.

The disorder and similar childhood spinal muscular atrophies are the leading cause of infant death from an inherited defect, and rank second only to cystic fibrosis as the most common type of inherited disorder.

The chronic form of the disease, which usually appears between the ages of 6 months and 17, has symptoms ranging from mild muscle weakness to inability to walk to premature death. It affects about 1 in 24,000 children worldwide.

A more severe type of the disorder, which is about as common as the chronic form, is usually fatal before age 2.

In a study published in the journal Nature, researchers from Tufts University medical school in Boston, New England Medical Center and Columbia University in New York said the genetic defect that causes chronic spinal muscular atrophy is apparently located on the “long arm” of Chromosome 5.