What is GNE Myopathy?
GNE Myopathy is a rare, inherited disease that causes progressive muscle weakness. The disease is caused by defects of the GNE gene. In this disorder the defect of the GNE enzyme disrupts the functioning of the sialic acid metabolic pathway, and interferes with normal muscle function.
GNE Myopathy typically affects young adults. One of the first signs of the disease includes inability to lift the front of the foot (foot drop). This may cause toes to drag while walking. As the disease progresses, it usually leads to physical disability. GNE Myopathy does not affect the muscles of the face, or swallowing ability. It does not typically affect the heart or breathing muscles.
GNE Myopathy is a rare disease estimated to affect around 6 in 1,000,000 people. It is found in populations worldwide but is more common in certain populations. Like many other rare diseases, GNE Myopathy is under diagnosed and many people with the disease remain undiagnosed.
GNE Myopathy has also been known as
HIBM (Hereditary Inclusion Body Myopathy), Nonaka Myopathy, Distal Myopathy with Rimmed Vacuoles, Inclusion Body Myopathy 2 (IBM 2), and Quadriceps-Sparing Myopathy. To facilitate diagnosis, GNE myopathy is the preferred name.
Here are some introductory videos about GNE Myopathy
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What Causes GNE Myopathy?
GNE Myopathy is caused by a genetic defect of the GNE gene. The defect disrupts the functioning of the sialic acid metabolic pathway and interferes with normal muscle function.
How Can I Get Tested?
If you have family members affected with GNE Myopathy, you can get tested by contacting a Genetics specialist.
If you experience any of the symptoms listed, you should be evaluated by doctors specializing in Neuromuscular Diseases or Medical Genetics. Here is a list of doctors familiar with GNE Myopathy. Ask for them or your personal physician to use a CLIA certified lab for diagnostic testing.
What are Some of the Symptoms?
Symptoms of the disease begin in young adults, typically between the ages of 20 and 40. Below is a list of common initial symptoms:
- Foot drop
- Frequently tripping
- Change in gait
- Difficulty in climbing stairs
- Difficulty in getting up from a seated position
- Difficulty in running
- Loss of balance
- Weakness in hands and shoulders
For more information, read this chapter on GNE Myopathy
Is GNE Myopathy known by any other names?
While the disease is officially now known as GNE Myopathy, previous names included:
HIBM – Hereditary Inclusion Body Myopathy
DMRV – Distal Myopathy with Rimmed Vacuoles
QSM – Quadriceps Sparing Myopathy
HIBM2 – Hereditary Inclusion Body Myopathy-Type 2
IBM2 – Inclusion Body Myopathy-Type 2
How Do I Know if I am a Carrier?
GNE Myopathy is an autosomal recessive disorder, which means that the parents of someone affected by GNE Myopathy are both carriers of the disease. Carriers are not affected by the disease, which means that they don’t show symptoms of the disease. But when two carriers have a child, there is a 25% chance with each pregnancy of having a child who has GNE Myopathy, a 50% chance that each child will be a carrier like his or her parents (and not have the disease), and a 25% chance that each child will not carry any mutation for the disease (meaning that he or she will not be a carrier nor will he or she have the disease).
It is possible to be tested at any time, but it is particularly important prior to becoming pregnant or during early pregnancy.
Testing is anonymous and can be performed with a painless cheek swab or collection of saliva.
What if I want to start a family and I am a carrier?
This is an important decision that you, your partner, and your doctor need to discuss in order to decide on the best option for you. Learn more about genetic screening here.
Is There a Treatment or Cure?
Currently there is no approved treatment for GNE Myopathy.
Clinical trials for ManNAc, a promising potential therapy are underway.
For a list of active clinical trials for GNE Myopathy, visit ClinicalTrials.gov
What is a Natural History Study?
Natural history studies allow scientists to collect data from patients to gain a better understanding of how GNE Myopathy affects patients. This is a way to contribute to advancing the general understanding of GNE Myopathy.
To participate in this type of study, you may need to travel to a hospital that conducts the natural history studies. Your medical and genetic information will be collected as well as blood samples, and tests of strength and function as needed.
For a list of other active Patient Registries and Natural History Studies of GNE Myopathy, click here.
For other resources that describe GNE Myopathy: