Distal hereditary motor neuropathy type V

Last updated
Distal hereditary motor neuropathy type V
Other namesdHMN V

Distal hereditary motor neuropathy type V is a particular type of neuropathic disorder. In general, distal hereditary motor neuropathies affect the axons of distal motor neurons and are characterized by progressive weakness and atrophy of muscles of the extremities. [1] It is common for them to be called "spinal forms of Charcot-Marie-Tooth disease (CMT)", because the diseases are closely related in symptoms and genetic cause. The diagnostic difference in these diseases is the presence of sensory loss in the extremities. [2] There are seven classifications of dHMNs, each defined by patterns of inheritance, age of onset, severity, and muscle groups involved. Type V (sometimes notated as Type 5) is a disorder characterized by autosomal dominance, weakness of the upper limbs that is progressive and symmetrical, and atrophy of the small muscles of the hands. [3]

Contents

Signs and symptoms

Onset usually occurs within the first two decades of life, commonly in the teenage years or the twenties. Life expectancy is normal.

High arch of the foot (pes cavus) seen in dHMN V and other related motor neuropathy disorders Charcot-marie-tooth foot.jpg
High arch of the foot (pes cavus) seen in dHMN V and other related motor neuropathy disorders

High arch of the foot (pes cavus) is common. Patients also have trouble controlling their hands, due to muscle loss on the thumb side of the index finger and palm below the thumb. [4] It is rare for a person with this disorder to lose the ability to walk, though changes in gait may occur later in life. [5]

Frequency of this disorder is unknown. [6]

Genetics

dHMN V has a pattern of autosomal dominance, meaning that only one copy of the gene is needed for the development of the disease. However, there is incomplete penetrance of this disorder, meaning that some individuals with the disease-causing mutations will not display any symptoms. [3] Mutations on chromosome 7 have been linked to this disease. It is allelic (i.e., caused by mutations on the same gene) with Charcot–Marie–Tooth disease and with Silver’s Syndrome, a disorder also characterized by small muscle atrophy in the hands. [1] [7] Another rare form of dHMN V is associated with a splicing mutation in REEP-1, a gene often associated with hereditary spastic paraplegia. [8]

Diagnosis

In an individual with dHMN V, electromyography will show pure motor neuropathy, patterns of weakness without upper motor neuron damage, in the hands. Tendon reflexes will also appear normal. [9] Clinical, electrophysiological, and pathological testing will show a lack of damage to sensory neurons, differentiating this disease from CMT. [10]

Treatment

Physical therapy is the predominant treatment of symptoms. Orthopedic shoes and foot surgery can be used to manage foot problems. [5]

References

  1. 1 2 Seo, Ah Jung; Park, Byung Sun; Jeong, Na Young; Kim, Doyen; Kim, Sunghoon; Park, Chan; Jung, Junyang; Huh, Youngbuhm (2014). "Adenoviral-mediated mouse model of motor impairment in distal spinal muscular atrophy type V". Animal Cells and Systems. 18 (5): 311–317. doi:10.1080/19768354.2014.950330. ISSN   1976-8354. S2CID   73528377.
  2. ↑ Middleton, L. T.; Christodoulou, K.; Mubaidin, A.; Zamba, E.; Tsingis, M.; Kyriacou, K.; Abu-Sheikh, S.; Kyriakides, T.; Neocleous, V.; Georgiou, D. M.; El-Khateeb, M.; Al-Qudah, A.; Horany, K. (1999). "Distal Hereditary Motor Neuronopathy of the Jerash Type". Annals of the New York Academy of Sciences. 883 (1 CHARCOT–MARIE): 439–442. Bibcode:1999NYASA.883..439M. doi:10.1111/j.1749-6632.1999.tb08604.x. ISSN   0077-8923. PMID   29086938. S2CID   27780275.
  3. 1 2 Rakočević-Stojanović, V.; Milić-Rašić, V.; Perić, S.; Baets, J.; Timmerman, V.; Dierick, I.; Pavlović, S.; De Jonghe, P. (2010). "N88S mutation in the BSCL2 gene in a Serbian family with distal hereditary motor neuropathy type V or Silver syndrome". Journal of the Neurological Sciences. 296 (1–2): 107–109. doi:10.1016/j.jns.2010.06.015. ISSN   0022-510X. PMID   20598714. S2CID   21874798.
  4. ↑ "Distal hereditary motor neuropathy, type V". Think Genetic. 10 June 2016. Archived from the original on 13 March 2017. Retrieved 5 November 2016.
  5. 1 2 Ito, Daisuke; Suzuki, Norihiro (2007). "Molecular pathogenesis of seipin/BSCL2-related motor neuron diseases". Annals of Neurology. 61 (3): 237–250. doi:10.1002/ana.21070. ISSN   0364-5134. PMID   17387721. S2CID   43661842.
  6. ↑ Reference, Genetics Home. "distal hereditary motor neuropathy, type V". Genetics Home Reference.
  7. ↑ Dubourg, O.; Azzedine, H.; Yaou, R. B.; Pouget, J.; Barois, A.; Meininger, V.; Bouteiller, D.; Ruberg, M.; Brice, A.; LeGuern, E. (12 June 2006). "The G526R glycyl-tRNA synthetase gene mutation in distal hereditary motor neuropathy type V". Neurology. 66 (11): 1721–1726. doi:10.1212/01.wnl.0000218304.02715.04. PMID   16769947. S2CID   22868888.
  8. ↑ Beetz, Christian; Pieber, Thomas R.; Hertel, Nicole; Schabhüttl, Maria; Fischer, Carina; Trajanoski, Slave; Graf, Elisabeth; Keiner, Silke; Kurth, Ingo; Wieland, Thomas; Varga, Rita-Eva; Timmerman, Vincent; Reilly, Mary M.; Strom, Tim M.; Auer-Grumbach, Michaela (2012). "Exome Sequencing Identifies a REEP1 Mutation Involved in Distal Hereditary Motor Neuropathy Type V". The American Journal of Human Genetics. 91 (1): 139–145. doi:10.1016/j.ajhg.2012.05.007. ISSN   0002-9297. PMC   3397265 . PMID   22703882.
  9. ↑ Antonellis, Anthony; Ellsworth, Rachel E.; Sambuughin, Nyamkhishig; Puls, Imke; Abel, Annette; Lee-Lin, Shih-Queen; Jordanova, Albena; Kremensky, Ivo; Christodoulou, Kyproula; Middleton, Lefkos T.; Sivakumar, Kumaraswamy; Ionasescu, Victor; Funalot, Benoit; Vance, Jeffery M.; Goldfarb, Lev G.; Fischbeck, Kenneth H.; Green, Eric D. (2003). "Glycyl tRNA Synthetase Mutations in Charcot-Marie-Tooth Disease Type 2D and Distal Spinal Muscular Atrophy Type V". The American Journal of Human Genetics. 72 (5): 1293–1299. doi:10.1086/375039. ISSN   0002-9297. PMC   1180282 . PMID   12690580.
  10. ↑ Pareyson, Davide; Marchesi, Chiara (2009). "Diagnosis, natural history, and management of Charcot–Marie–Tooth disease". The Lancet Neurology. 8 (7): 654–667. doi:10.1016/S1474-4422(09)70110-3. ISSN   1474-4422. PMID   19539237. S2CID   665324.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.