Types
Defining Characteristics
Pseudohypertrophy (large calves), scoliosis, lumbar lordosis, protuberant abdomen, toe walking, Gower’s sign, mental deficits
Disease Development
Caused by X-linked recessive mutation of dystrophin, resulting in absent (or <5%) dystrophin. W/o dystrophin, the sarcolemic membranes are leaky, there's secondary inflammation from necrosis, and cycles of degeneration & regeneration.
Potential Causes
Absent dystrophin
Epidemiology
Most common MD, especially in children
1/3000 live births
Lab/Imaging
Histology? Increased CT, fibrofatty and macrophage infiltration, variable muscle fiber size and abnl cells, bluish fibers are regenerating (inc DNA)
CK levels 10-100x>nl
Conventional Treatment
Steroids at early age prolongs ability to walk
Complications
Associated w/ dilated cardiomyopathy
No cure! Limited life expectancy