Spinal Muscular atrophy causes: Difference between revisions

Jump to navigation Jump to search
No edit summary
No edit summary
Line 22: Line 22:
{{Editor Help}}
{{Editor Help}}


The most common form of SMA is caused by mutation of the SMN gene, and manifests over a wide range of severity affecting infants through adults. This spectrum has been divided into three groups, depending on the age of onset, and are as followed:
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) <ref name="pmid8551862">{{cite journal| author=Clermont O, Burlet P, Lefebvre S, Bürglen L, Munnich A, Melki J| title=SMN gene deletions in adult-onset spinal muscular atrophy. | journal=Lancet | year= 1995 | volume= 346 | issue= 8991-8992 | pages= 1712-3 | pmid=8551862 | doi= | pmc= | url= }} </ref>. 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 (<ref name="pmid10607836">{{cite journal| author=Lorson CL, Androphy EJ| title=An exonic enhancer is required for inclusion of an essential exon in the SMA-determining gene SMN. | journal=Hum Mol Genet | year= 2000 | volume= 9 | issue= 2 | pages= 259-65 | pmid=10607836 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10607836 }} </ref>). The number of copies of SMN2 per chromosome 5 and the amount of SMN protein are inversely correlated with the severity of disease (<ref name="pmid11791208">{{cite journal| author=Feldkötter M, Schwarzer V, Wirth R, Wienker TF, Wirth B| title=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. | journal=Am J Hum Genet | year= 2002 | volume= 70 | issue= 2 | pages= 358-68 | pmid=11791208 | doi=10.1086/338627 | pmc=PMC419987 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=11791208  }} </ref>, <ref name="pmid11839954">{{cite journal| author=Mailman MD, Heinz JW, Papp AC, Snyder PJ, Sedra MS, Wirth B et al.| title=Molecular analysis of spinal muscular atrophy and modification of the phenotype by SMN2. | journal=Genet Med | year= 2002 | volume= 4 | issue= 1 | pages= 20-6 | pmid=11839954 | doi= | pmc= | url= }} </ref>). 95% of patients of SMA with SMA have deletions of the SMN1 gene whereas others have intragenic, denovo mutation or [[gene conversion]] (<ref name="pmid15470363">{{cite journal| author=Ogino S, Wilson RB, Gold B| title=New insights on the evolution of the SMN1 and SMN2 region: simulation and meta-analysis for allele and haplotype frequency calculations. | journal=Eur J Hum Genet | year= 2004 | volume= 12 | issue= 12 | pages= 1015-23 | pmid=15470363 | doi=10.1038/sj.ejhg.5201288 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15470363  }} </ref>, <ref name="pmid17761649">{{cite journal| author=Prior TW| title=Spinal muscular atrophy diagnostics. | journal=J Child Neurol | year= 2007 | volume= 22 | issue= 8 | pages= 952-6 | pmid=17761649 | doi=10.1177/0883073807305668 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17761649  }} </ref>).
 
*'''Infantile SMA - Type I or [[Werdnig-Hoffmann disease]]''' (generally 0-6 months). SMA type I, also known as severe infantile SMA or Werdnig Hoffmann disease, is the most severe, and manifests in the first year of lifeThis type generally onsets quickly and unexpectedly after birth; babies diagnosed with Type I SMA do not generally live past one year of age. Pneumonia is considered the ultimate cause of death due to deterioration of survival motor neurons; these neurons trigger improper functioning of the major bodily organ systems, particularly respiratory (e.g. breathing, ridding of pooled secretions inside lungs).
*'''Intermediate SMA - Type II''' (generally 7-18 months). Type II SMA, or intermediate SMA, describes those children who are never able to stand and walk, but who are able to maintain a sitting position at least some time in their life. The onset of weakness is usually recognized some time between 6 and 18 months.  
*'''Adult SMA - Type III or [[Kugelberg-Welander disease]]''' (generally >18 months). SMA type 3 describes those who are able to walk at some time.


==References==
==References==

Revision as of 18:27, 21 June 2011

Spinal Muscular atrophy causes
ICD-10 G12
ICD-9 335.0-335.1
OMIM 253300 253550 253400 271150
DiseasesDB 14093 Template:DiseasesDB2 Template:DiseasesDB2
MeSH D009134

WikiDoc Resources for Spinal Muscular atrophy causes

Articles

Most recent articles on Spinal Muscular atrophy causes

Most cited articles on Spinal Muscular atrophy causes

Review articles on Spinal Muscular atrophy causes

Articles on Spinal Muscular atrophy causes in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Spinal Muscular atrophy causes

Images of Spinal Muscular atrophy causes

Photos of Spinal Muscular atrophy causes

Podcasts & MP3s on Spinal Muscular atrophy causes

Videos on Spinal Muscular atrophy causes

Evidence Based Medicine

Cochrane Collaboration on Spinal Muscular atrophy causes

Bandolier on Spinal Muscular atrophy causes

TRIP on Spinal Muscular atrophy causes

Clinical Trials

Ongoing Trials on Spinal Muscular atrophy causes at Clinical Trials.gov

Trial results on Spinal Muscular atrophy causes

Clinical Trials on Spinal Muscular atrophy causes at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Spinal Muscular atrophy causes

NICE Guidance on Spinal Muscular atrophy causes

NHS PRODIGY Guidance

FDA on Spinal Muscular atrophy causes

CDC on Spinal Muscular atrophy causes

Books

Books on Spinal Muscular atrophy causes

News

Spinal Muscular atrophy causes in the news

Be alerted to news on Spinal Muscular atrophy causes

News trends on Spinal Muscular atrophy causes

Commentary

Blogs on Spinal Muscular atrophy causes

Definitions

Definitions of Spinal Muscular atrophy causes

Patient Resources / Community

Patient resources on Spinal Muscular atrophy causes

Discussion groups on Spinal Muscular atrophy causes

Patient Handouts on Spinal Muscular atrophy causes

Directions to Hospitals Treating Spinal Muscular atrophy causes

Risk calculators and risk factors for Spinal Muscular atrophy causes

Healthcare Provider Resources

Symptoms of Spinal Muscular atrophy causes

Causes & Risk Factors for Spinal Muscular atrophy causes

Diagnostic studies for Spinal Muscular atrophy causes

Treatment of Spinal Muscular atrophy causes

Continuing Medical Education (CME)

CME Programs on Spinal Muscular atrophy causes

International

Spinal Muscular atrophy causes en Espanol

Spinal Muscular atrophy causes en Francais

Business

Spinal Muscular atrophy causes in the Marketplace

Patents on Spinal Muscular atrophy causes

Experimental / Informatics

List of terms related to Spinal Muscular atrophy causes

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [2] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.

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) [1]. 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 ([2]). The number of copies of SMN2 per chromosome 5 and the amount of SMN protein are inversely correlated with the severity of disease ([3], [4]). 95% of patients of SMA with SMA have deletions of the SMN1 gene whereas others have intragenic, denovo mutation or gene conversion ([5], [6]).

References

  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. Prior TW (2007). "Spinal muscular atrophy diagnostics". J Child Neurol. 22 (8): 952–6. doi:10.1177/0883073807305668. PMID 17761649.

External links

  • Template:NINDS
  • 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

Template:Diseases of the nervous system Template:SIB

da:Spinal muskulær atrofi de:Spinale Muskelatrophie el:Νωτιαία μυϊκή ατροφία nl:Spinale Musculaire Atrofieën fi:Spinaaliset lihasatrofiat sv:Spinal muskelatrofi


Template:WikiDoc Sources