Inherited Myopathies: Types

00:00 So as we think about inherited myopathies, we can group them into 5 main categories. There are muscular dystrophies. These are progressive conditions where patients get weak. It follows a typical myopathic pattern of proximal weakness, absent sensory findings, and normal reflexes and progresses over time. With many muscular dystrophies, we see increase in CK and that should guide us towards evaluating these genetic causes of muscle disorder. This is different from congenital myopathies, which will be the second group to review. Those are static myopathies. They cause weakness that tends to not progress over time. Ion channel disorders are intermittent so patients are weak sometimes and not weak other times, and that's an important tip off to test for ion channel disorders. And then the 2 final buckets are mitochondrial myopathies and metabolic myopathies, which typically present with rhabdomyolysis. The focus of our discussion in the following lectures will be on muscular dystrophies and congenital myopathies. The ion channel disorders, the mitochondrial, the metabolic myopathies are less common and so we're going to focus on the first 2 categories of this disorder.