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Review
. 2015 Nov;33(4):831-46.
doi: 10.1016/j.ncl.2015.07.004.

Spinal Muscular Atrophy

Stephen J Kolb  1 , John T Kissel  2
Affiliations
Review

Spinal Muscular Atrophy

Stephen J Kolb et al. Neurol Clin. 2015 Nov.

Abstract

Spinal muscular atrophy is an autosomal-recessive disorder characterized by degeneration of motor neurons in the spinal cord and caused by mutations in the survival motor neuron 1 gene, SMN1. The severity of SMA is variable. The SMN2 gene produces a fraction of the SMN messenger RNA (mRNA) transcript produced by the SMN1 gene. There is an inverse correlation between SMN2 gene copy number and clinical severity. Clinical management focuses on multidisciplinary care. Preclinical models of SMA have led to an explosion of SMA clinical trials that hold great promise of effective therapy in the future.

Keywords: Motor neuron; SMN1; SMN2; Spinal muscular atrophy; Survival motor neuron gene.

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Figures

Figure 1
Figure 1
Spinal muscular atrophy type 1
Figure 2
Figure 2
Spinal Muscular Atrophy type 2
Figure 3
Figure 3
Spinal Muscular Atrophy type 3
Figure 4
Figure 4. Schematic of SMN gene
Schematic diagram of the human SMN1 and SMN2 genes and the resultant pre-mRNAs. Patients with SMA have deletions or mutations in both copies of SMN1. The SMN2 gene is expressed, however the majority of the resultant SMN2 pre-mRNA lacks exon 7 because of a C-to-T transition at position 6 of exon 7. The truncated SMN protein is unstable and non-functional. A small proportion of full-length mRNA containing exon 7 is produced by from the SMN2 pre-mRNA, however resulting in full-length SMN protein that is functional
See this image and copyright information in PMC

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