Jerash type distal hereditary motor neuropathy is a genetic disorder that affects the muscles in the body. The symptoms of the disorder begin to appear around age 6-10 years old. The main symptom of this disorder is a weakening and slow wasting away of muscles. First, weakness occurs in the lower limbs and within a few years the upper limbs become affected. People affected with this disorder have difficulties in moving their arms and legs, walking, and preforming normal muscle movements.
This disorder is caused by a mutation in the SIGMAR1 gene. This gene is important for muscles to work and grow properly. The disorder is passed on in an autosomal recessive manner. This means that a person must have a mutation in both copies of their SIGMA1 gene in order to have the disorder. If both parents have only one mutation they are called carriers because they “carry” a mutated copy, these individuals usually do not show any symptoms. If two people are carriers, they have a 1 in 4 or 25% chance of having a child with this disorder.
Treatment varies based on a case-by-case basis. If you or a family member has been diagnosed with Jerash type distal hereditary motor neuropathy, talk with your doctor about the most current treatment options. Support groups are also good resources of support and information.
Description Last Updated: Jan 27, 2018