Distal hereditary motor neuropathy, type V

Distal hereditary motor neuropathy, type V is a progressive disorder that affects nerve cells in the spinal cord and weakens muscles in the hands and feet.

Symptoms of distal hereditary motor neuropathy, type V usually begin during adolescence, but onset varies from infancy to the mid-thirties. Cramps in the hand induced by the cold are often the initial symptom. The main characteristics of this disorder are weakness and wasting away (atrophy) of hand muscles, specifically on the thumb side of the index finger and in the palm at the base of the thumb. Foot abnormalities, such as a high arch (pes cavus), are also common. People with this disorder lead active lives and have normal life expectancies.

How common is distal hereditary motor neuropathy, type V?

The incidence of distal hereditary motor neuropathy, type V is unknown; only a small number of cases have been reported.

What genes are related to distal hereditary motor neuropathy, type V?

Mutations in the BSCL2 and GARS genes cause distal hereditary motor neuropathy, type V.

The BSCL2 gene provides instructions for making a protein called seipin, whose function is unknown. Mutations in the BSCL2 gene likely alter the shape and structure of seipin. It is unclear how the altered seipin protein impairs nerves that control muscles in the hands and feet.

The GARS gene provides instructions for making an enzyme that is involved in the production (synthesis) of proteins. It remains unclear how GARS mutations lead to distal hereditary motor neuropathy, type V. GARS mutations may disrupt protein synthesis in nerve cells, which impairs the function of the nerve fiber (axon) that transmits nerve impulses. As a result, nerve cells slowly lose the ability to communicate with muscles in the hands and feet.

Read more about the BSCL2 and GARS genes.

How do people inherit distal hereditary motor neuropathy, type V?

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.

Where can I find information about treatment for distal hereditary motor neuropathy, type V?

These resources address the management of distal hereditary motor neuropathy, type V, and may include treatment providers.

GeneReviews: BSCL2-Related Neurologic Disorders Gene Reviews: Charcot-Marie-Tooth Neuropathy Type 2D/Distal Spinal Muscular Atrophy V MedlinePlus Encyclopedia: high-arched foot

Where can I find additional information about distal hereditary motor neuropathy, type V?

You may find the following resources about distal hereditary motor neuropathy, type V, helpful. These materials are written for the general public.

• MedlinePlus - Health information (2 links)

You may also be interested in these resources, which are designed for healthcare professionals and researchers.

• Gene Reviews - Clinical summary (2 links)
• Gene Tests - DNA tests ordered by healthcare professionals (2 links)
• PubMed - Recent literature
• OMIM - Genetic disorder catalog

What other names do people use for distal hereditary motor neuropathy, type V?

• DHMN-V
• distal spinal muscular atrophy, type V
• DSMAV
• HMN V
• neuronopathy, distal hereditary motor, type V
• spinal muscular atrophy, distal type V
• spinal muscular atrophy, distal, with upper limb predominance

See How are genetic conditions and genes named? in the Handbook.

What if I still have specific questions about distal hereditary motor neuropathy, type V?

• See How can I find a genetics professional in my area? in the Handbook.
• Ask the Genetic and Rare Diseases Information Center.
• Submit your question to Ask the Geneticist.

Where can I find general information about genetic conditions?

The Handbook provides basic information about genetics in clear language.

• What does it mean if a disorder seems to run in my family?
• What are the different ways in which a genetic condition can be inherited?
• If a genetic disorder runs in my family, what are the chances that my children will have the condition?
• Why are some genetic conditions more common in particular ethnic groups?

These links provide additional genetics resources that may be useful.

• Genetics and health
• Resources for Patients and Families
• Resources for Health Professionals

What glossary definitions help with understanding distal hereditary motor neuropathy, type V?

atrophy ; autosomal ; autosomal dominant ; axons ; cell ; distal ; enzyme ; gene ; incidence ; motor ; mutation ; nerve cell ; neuropathy ; pes cavus ; protein ; symptom ; synthesis ; wasting

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

See also Understanding Medical Terminology.

References

These sources were used to develop the Genetics Home Reference condition summary on distal hereditary motor neuropathy, type V.

• Antonellis A, Ellsworth RE, Sambuughin N, Puls I, Abel A, Lee-Lin SQ, Jordanova A, Kremensky I, Christodoulou K, Middleton LT, Sivakumar K, Ionasescu V, Funalot B, Vance JM, Goldfarb LG, Fischbeck KH, Green ED. Glycyl tRNA synthetase mutations in Charcot-Marie-Tooth disease type 2D and distal spinal muscular atrophy type V. Am J Hum Genet. 2003 May;72(5):1293-9. Epub 2003 Apr 10. PubMed citation
• Auer-Grumbach M, Loscher WN, Wagner K, Petek E, Korner E, Offenbacher H, Hartung HP. Phenotypic and genotypic heterogeneity in hereditary motor neuronopathy type V: a clinical, electrophysiological and genetic study. Brain. 2000 Aug;123 ( Pt 8):1612-23. PubMed citation
• Dubourg O, Azzedine H, Yaou RB, Pouget J, Barois A, Meininger V, Bouteiller D, Ruberg M, Brice A, LeGuern E. The G526R glycyl-tRNA synthetase gene mutation in distal hereditary motor neuropathy type V. Neurology. 2006 Jun 13;66(11):1721-6. Erratum in: Neurology. 2006 Aug 22;67(4):727. PubMed citation
• Irobi J, De Jonghe P, Timmerman V. Molecular genetics of distal hereditary motor neuropathies. Hum Mol Genet. 2004 Oct 1;13 Spec No 2:R195-202. Review. PubMed citation
• Sivakumar K, Kyriakides T, Puls I, Nicholson GA, Funalot B, Antonellis A, Sambuughin N, Christodoulou K, Beggs JL, Zamba-Papanicolaou E, Ionasescu V, Dalakas MC, Green ED, Fischbeck KH, Goldfarb LG. Phenotypic spectrum of disorders associated with glycyl-tRNA synthetase mutations. Brain. 2005 Oct;128(Pt 10):2304-14. Epub 2005 Jul 13. PubMed citation
• Windpassinger C, Auer-Grumbach M, Irobi J, Patel H, Petek E, Horl G, Malli R, Reed JA, Dierick I, Verpoorten N, Warner TT, Proukakis C, Van den Bergh P, Verellen C, Van Maldergem L, Merlini L, De Jonghe P, Timmerman V, Crosby AH, Wagner K. Heterozygous missense mutations in BSCL2 are associated with distal hereditary motor neuropathy and Silver syndrome. Nat Genet. 2004 Mar;36(3):271-6. Epub 2004 Feb 22. PubMed citation