ABSTRACT
The spinal muscular atrophies are a group of mostly inherited disorders selectively
affecting the lower motor neuron. There is a wide degree of clinical and genetic heterogeneity
that must be taken into account when giving prognostic information. Autosomal recessive
childhood proximal SMA is the commonest form and is due to mutations in a gene encoding
a novel protein, SMN, that appears to play a critical role in RNA metabolism but has
also been shown to interact with actin-binding proteins and mediators of programmed
cell death. The identification of the genetic basis of SMA has resulted in advances
for prenatal diagnosis and in new insights into motor neuron biology. The chromosomal
location of two of the rarer dominant forms of SMA has been found. Identification
of the molecular pathophysiology of lower motor neuron syndromes can be expected to
aid in the development of therapy for these disabling disorders.
KEYWORD
Spinal muscular atrophy - survival motor neuron - motor neuron
