The pathology underlying the observable characteristics of DSMA1 is cell body degeneration of motor nerves. Specifically, the anterior horn α-motorneurons degenerate within the first six months of life leading to a variety of symptoms. Muscle deterioration increases at around<unk> –2 years of age, resulting in reduced motor function. The most severely affected muscles include facial muscles and the tongue (which may develop a twitch due to hypoglossal nerve paralysis). Reduced pain sensation and excessive sweating are sometimes observed. Non-ambulant patients may develop pressure ulcers, severe constipation, urinary incontinence, and (rarely) reflux nephropathy in the advanced stages of the disease.
Distal spinal muscular atrophy type 1
Distal spinal muscular atrophy type 2
Jokela type spinal muscular atrophy
Spinal muscular atrophy
X-linked spinal muscular atrophy type 2
Fukuyama congenital muscular dystrophy
Becker muscular dystrophy
Ullrich congenital muscular dystrophy