Skip Navigation
Genetics Home Reference: your guide to understanding genetic conditions About   Site Map   Contact Us
 
Home A service of the U.S. National Library of Medicine®
 
 
Printer-friendly version
Distal hereditary motor neuropathy, type V

Distal hereditary motor neuropathy, type V

Reviewed August 2009

What is distal hereditary motor neuropathy, type V?

Distal hereditary motor neuropathy, type V is a progressive disorder that affects nerve cells in the spinal cord. It results in muscle weakness and affects movement of 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 brought on by exposure to cold temperatures are often the initial symptom.

The characteristic features of distal hereditary motor neuropathy, type V are weakness and wasting (atrophy) of muscles of the hand, 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, and some affected individuals eventually develop problems with walking (gait disturbance). People with this disorder 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 structure of seipin, causing it to fold into an incorrect 3-dimensional shape. Research findings indicate that misfolded seipin proteins accumulate in the endoplasmic reticulum, which is a structure inside the cell that is involved in protein processing and transport. This accumulation likely damages and kills motor neurons (specialized nerve cells in the brain and spinal cord that control muscle movement), leading to muscle weakness in the hands and feet.

The GARS gene provides instructions for making an enzyme called glycyl-tRNA synthetase, which is involved in the production (synthesis) of proteins. It is unclear how GARS gene mutations lead to distal hereditary motor neuropathy, type V. The mutations probably reduce the activity of glycyl-tRNA synthetase. A reduction in the activity of this enzyme may impair transmission of 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 diagnosis or management of distal hereditary motor neuropathy, type V?

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

You might also find information on the diagnosis or management of distal hereditary motor neuropathy, type V, in Educational resources and Patient support.

General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.

To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.

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.

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

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

  • DHMN-V
  • distal hereditary motor neuronopathy type 5
  • distal hereditary motor neuronopathy, type V
  • distal spinal muscular atrophy, type V
  • DSMAV
  • HMN V
  • spinal muscular atrophy, distal type V
  • spinal muscular atrophy, distal, with upper limb predominance

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines and How are genetic conditions and genes named? in the Handbook.

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

Where can I find general information about genetic conditions?

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

atrophy ; autosomal ; autosomal dominant ; cell ; distal ; endoplasmic reticulum ; enzyme ; gait ; gene ; hereditary ; incidence ; inherited ; motor ; neuropathy ; pes cavus ; protein ; symptom ; synthesis ; tRNA ; wasting

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

See also Understanding Medical Terminology.

References (10 links)

 

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.

 
Reviewed: August 2009
Published: October 27, 2014