But why should an anticholesterol drug weaken muscles in the arms and legs? Recently, two groups of scientists stumbled upon an answer. They didn’t set out to study statins. They weren’t studying cholesterol at all. They were hunting for genes behind a rare disease called limb girdle muscle dystrophy. both teams tracked the disease through a handful of families in the U.S. and a Bedouin family in Israel, their suspicions separately landed on mutations in a gene encoding a particularly intriguing enzyme. The enzyme is known as HMG-CoA reductase, and to doctors, it is not obscure. It is, in fact, the very enzyme that statins block in the process of halting cholesterol production. And so, the answers to two mysteries suddenly became clear at once: Dysfunction in this enzyme causes muscle weakness from both limb girdle muscular dystrophy and statins. This connection between a rare disease and a common drug stunned the researchers. thats the basic Idea.