Spinal muscular atrophy with progressive myoclonic epilepsy

Spinal muscular atrophy with progressive myoclonic epilepsy
Other namesHereditary myoclonus-progressive distal muscular atrophy syndrome
Autosomal recessive - en.svg
This condition is inherited in an autosomal recessive manner

Spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME), sometimes called Jankovic–Rivera syndrome, is a very rare neurodegenerative disease whose symptoms include slowly progressive muscle wasting (atrophy), predominantly affecting proximal muscles, combined with denervation and myoclonic seizures.[1] Only 12 known families are described in scientific literature to have SMA-PME.[2]

SMA-PME is associated with a missense mutation (c.125C→T) or deletion in exon 2 of the ASAH1 gene and is inherited in an autosomal recessive manner.[3] SMA-PME is closely related to a lysosomal disorder disease called Farber lipogranulomatosis.[4] As with many genetic disorders, there is no known cure to SMA-PME.

The condition was first described in 1979 by American researchers Joseph Jankovic and Victor M. Rivera.[5]

ASAH1 Gene

The ASAH1 Gene codes for acid ceramidase which is an enzyme found in lysosomes. The lysosome breaks down acid ceramidase and the fatty acid component [6] is then used to produce myelin. Myelin is a coating around the nerves in the body which help transfer signals from nerve cell to nerve cell and increase transmission rate.[7] In patients with SMA-PME, the cermidase function is reduced to only be 33.33% effective.[2] The lack of myelin resulting from the lack of acid ceramidase break down leads to nerve cell damage.

See also


  1. ^ Haliloglu, G.; Chattopadhyay, A.; Skorodis, L.; Manzur, A.; Mercuri, E.; Talim, B.; Akçören, Z.; Renda, Y.; Muntoni, F.; Topaloğlu, H. (2002). "Spinal Muscular Atrophy with Progressive Myoclonic Epilepsy: Report of New Cases and Review of the Literature". Neuropediatrics. 33 (6): 314–319. doi:10.1055/s-2002-37087. PMID 12571787.
  2. ^ a b Reference, Genetics Home. "Spinal muscular atrophy with progressive myoclonic epilepsy". Genetics Home Reference. Retrieved 2018-09-24.
  3. ^ Zhou, J.; Tawk, M.; Tiziano, F. D.; Veillet, J.; Bayes, M.; Nolent, F.; Garcia, V.; Servidei, S.; Bertini, E.; Castro-Giner, F.; Renda, Y.; Carpentier, S. P.; Andrieu-Abadie, N.; Gut, I.; Levade, T.; Topaloglu, H.; Melki, J. (2012). "Spinal Muscular Atrophy Associated with Progressive Myoclonic Epilepsy is Caused by Mutations in ASAH1". The American Journal of Human Genetics. 91 (1): 5–14. doi:10.1016/j.ajhg.2012.05.001. PMC 3397266. PMID 22703880.
  4. ^ Gan, Joanna J.; Garcia, Virginie; Tian, Jane; Tagliati, Michele; Parisi, Joseph E.; Chung, Jeffrey M.; Lewis, Richard; Baloh, Robert; Levade, Thierry; Pierson, Tyler Mark (2015-12-01). "Acid ceramidase deficiency associated with spinal muscular atrophy with progressive myoclonic epilepsy". Neuromuscular Disorders. 25 (12): 959–963. doi:10.1016/j.nmd.2015.09.007. ISSN 0960-8966. PMID 26526000.
  5. ^ Jankovic, J.; Rivera, V. M. (1979). "Hereditary myoclonus and progressive distal muscular atrophy". Annals of Neurology. 6 (3): 227–231. doi:10.1002/ana.410060309. PMID 534421.
  6. ^ Park, Jae-Ho; Schuchman, Edward H. (December 2006). "Acid ceramidase and human disease". Biochimica et Biophysica Acta (BBA) - Biomembranes. 1758 (12): 2133–2138. doi:10.1016/j.bbamem.2006.08.019. ISSN 0006-3002. PMID 17064658.
  7. ^ Morell, Pierre; Quarles, Richard H. (1999). "The Myelin Sheath". Basic Neurochemistry: Molecular, Cellular and Medical Aspects. 6th Edition.

Further reading

External links

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Media files used on this page

Autosomal recessive - en.svg
Author/Creator: Domaina, Kashmiri and SUM1, Licence: CC BY-SA 3.0
Autosomal recessive inheritance (English version)