Metabolic Myopathies

Research

MDA-funded scientists are pursuing a number of promising leads in their quest to understand the causes of the metabolic diseases of muscle.

To date, scientists have isolated all of the genes involved in the metabolic myopathies described here, and their genetic codes have been unraveled, offering insight into how particular gene defects lead to disease. In addition, isolation of genes has allowed researchers to begin experiments with gene therapy, a potential cure for some metabolic diseases.

The knowledge MDA-funded researchers are obtaining about the mechanisms by which metabolic gene defects cause disease may lead to other strategies for prevention and treatment. MDA’s extensive research program includes studies to help in developing new treatments for metabolic diseases of muscle, such as strategies designed to replace the enzymes that are missing in these disorders.

Efforts to develop such "enzyme replacement therapies" already have been rewarded with the U.S. Food and Drug Administration’s approval in 2006 of Myozyme, a laboratory-modified acid maltase enzyme developed by Genzyme of Cambridge, Mass., with the support of MDA, for the treatment of Pompe disease.

In 2010, Genzyme began marketing Lumizyme, a similar drug. Since Myozyme and Lumizyme became available, the outlook for people of all ages with Pompe disease is considerably brighter.

Targets now being pursued in research include:

• better diagnosis of metabolic diseases to allow better identification of at-risk individuals and earlier treatment;
• continued examination of the role of exercise and diet in metabolic diseases;
• development of animal models of metabolic diseases, both to improve understanding of the diseases and to test possible treatments;
• development of enzyme replacement therapies in addition to Myozyme for enzyme deficiencies; and
• development of gene therapies for metabolic diseases.

For a look at diet considerations in acid maltase deficiency (Pompe disease), carnitine palmityl transferase deficiency and phosphorylase deficiency (McArdle disease), see What Not to Eat: Some consensus, much controversy about diet in three metabolic diseases.