Spinal muscular atrophy genetics
Spinal Muscular Atrophy Microchapters
Spinal muscular atrophy genetics Resources
Spinal muscular atrophy is caused by mutation in SMN (survival motor neuron) gene present on chromosome 5q 13 in 98.6% of patients. The chromosome 5 contains an inverted duplication that contains the SMN1 gene (this is mutated in patients with SMA) and the SMN2 gene (a duplication of SMN1 that differs from it by only five nucleotides) . Due to this difference in nucleotide in SMN2 gene, a truncated (Survival motor neuron) SMN protein is produced, much of which is non-functional and thus degraded. However, some of the SMN2 gene skips this and are able to produce some functional protein (). The number of copies of SMN2 per chromosome 5 and the amount of SMN protein are inversely correlated with the severity of disease (, ). 95% of patients of SMA with SMA have deletions of the SMN1 gene whereas others have intragenic, denovo mutation or gene conversion (, ).
- Clermont O, Burlet P, Lefebvre S, Bürglen L, Munnich A, Melki J (1995). "SMN gene deletions in adult-onset spinal muscular atrophy". Lancet. 346 (8991–8992): 1712–3. PMID 8551862.
- Lorson CL, Androphy EJ (2000). "An exonic enhancer is required for inclusion of an essential exon in the SMA-determining gene SMN". Hum Mol Genet. 9 (2): 259–65. PMID 10607836.
- Feldkötter M, Schwarzer V, Wirth R, Wienker TF, Wirth B (2002). "Quantitative analyses of SMN1 and SMN2 based on real-time lightCycler PCR: fast and highly reliable carrier testing and prediction of severity of spinal muscular atrophy". Am J Hum Genet. 70 (2): 358–68. doi:10.1086/338627. PMC 419987. PMID 11791208.
- Mailman MD, Heinz JW, Papp AC, Snyder PJ, Sedra MS, Wirth B; et al. (2002). "Molecular analysis of spinal muscular atrophy and modification of the phenotype by SMN2". Genet Med. 4 (1): 20–6. PMID 11839954.
- Ogino S, Wilson RB, Gold B (2004). "New insights on the evolution of the SMN1 and SMN2 region: simulation and meta-analysis for allele and haplotype frequency calculations". Eur J Hum Genet. 12 (12): 1015–23. doi:10.1038/sj.ejhg.5201288. PMID 15470363.
- Prior TW (2007). "Spinal muscular atrophy diagnostics". J Child Neurol. 22 (8): 952–6. doi:10.1177/0883073807305668. PMID 17761649.
- SMA Support
- Spinal Muscular Atrophy - Fight SMA - An international nonprofit dedicated to finding a treatment or cure for spinal muscular atrophy. Visit Fight SMA's website and also the Spinal Muscular Atrophy Blog for the latest news and research information about the leading genetic killer of children under two.
- Families of Spinal Muscular Atrophy - An international nonprofit dedicated to advancing research and supporting individuals and families with sma. FSMA has a web site with news, information and message boards for individuals to post questions. FSMA is one of the largest US private funders of SMA research and has more than 30 chapters worldwide.FSMA
- SMA Trust - a UK registered charity working to fund medical research into Spinal Muscular Atrophy
- Jennifer Trust for Spinal Muscular Atrophy - A national charity in the UK dedicated both to supporting people affected by SMA, and investing in essential research into causes, treatments and eventually a cure for the condition