Is limb-girdle muscular dystrophy over-diagnosed?
LS: Not so many years ago, LGMD was a frequent diagnosis in the clinics, because anything that presented with weakness of the pelvic and shoulder girdles, and which was slowly progressive, was often called that. But we now know that, in addition to polymyositis, there are a host of other diseases that can cause this same set of symptoms, and can look, at least superficially, like LGMD. Chronic spinal muscular atrophy used to be, and possibly still is, called LGMD. Some of the metabolic myopathies, for example hereditary carnitine deficiency, can look like LGMD as well. It sounds like there isn’t much that actually is limb-girdle dystrophy! LS: Oh no, there are many cases of genetically identifiable LGMD. But it has been overdiagnosed in the past. Are ALS and SMA often confused with one another? LS: They shouldn’t be, though certainly if you have adult-onset SMA it could be mistaken for the early stages of lower motor neuron ALS. But that wouldn’t be common. (Motor neurons are specializ
