HIBM (Hereditary Inclusion Body Myopathies) are a group of genetic disorders , which are uncommon in the general world population. HIBM causes progressive muscle wasting and weakness that can lead to severe disability. The autosomal recessive form GNE Myopathy, (IBM2 or DMRV Nonaka Myopathy) is more common in people with a Middle Eastern, Jewish or Japanese heritage, but patients can be found in every community. HIBM has been identified in other minorities throughout the world. Patients of Asian (Japanese, Korean, Chinese and others), European, and South American origin, as well as Muslim patients in the Middle Eastern, Palestinian, and Iranian origin, have been identified. In Japan and many East Asian countries, this disorder is known as Distal Myopathy with Rimmed Vacuoles (DMRV).
HIBM causes progressive muscle weakness and wasting. Muscle wasting usually starts around the age of 20 - 30 years, although we have seen young onset at 17 and old onset at 52. As such, it affects the most productive times of a persons life. It can lead to severe disability within 10 - 15 years, confining many patients to a wheelchair. The weakness and severity can vary from person to person. In some, weakness in the legs is noticed first. In few others, the hands are weakened more rapidly than the legs. Weakness is progressive, which means the muscle become weaker over time. HIBM does not seem to affect the brain, internal organs or sensation. The quadriceps are relatively spared, and remain strong until the late stages of disease, which is the reason HIBM is often referred to as Quadriceps Sparing Myopathy (QSM).
Some early signs of HIBM includes:
Since the disorder is recessive (both alleles of the gene are damaged), anyone may become affected, even with healthy parents and parental families. HIBM is more common in people with a Middle Eastern, Jewish or Japanese heritage, but patients can be found in every community. We do offer genetic testing, for those who suspect to be affected or have a higher risk of being affected.
Currently, there are no effective treatments for HIBM. Researchers at Hadassah, USC, UCLA, UCSD, Johns Hopkins University, Canada, NIH, and Japan are contributing towards finding an effective treatment. You may also wish to look at Developing Rex which describes how scientists develop treatment for a disease. With proper financial support and awareness we can speed up research significantly.
Yes. Based on preliminary scientific findings, we believe it is less difficult to develop an intervention for HIBM than for many common myopathic conditions. This is because HIBM is associated with mutations on an enzyme that is expressed at low levels in skeletal muscle, but many other common muscle wasting conditions are caused by mutations on cellular structural proteins which are expressed at very high levels in muscle.
Current treatment theories revolve around the following basic concepts:
1. Substrate/Product based therapies: These theories involve administration of small molecules that would increase intramuscular pools of a compound known as Sialic Acid. It may involve administration of Sialic Acid rich compounds (e.g. IVIG - IntraVenous Immune Globulins), Sialic Acid precursors, or other derivatives. Currently, this method is most likely to reach clinical trials in the shortest time.
2.Gene or gene based therapies: These theories involve administration of normal or hyperactive forms of the GNE/MNK enzyme (the enzyme that is mutated in HIBM).
3.Cell based therapies: These theories involve use of specialized stem cells capable of regenerating muscle and expressing the normal or hyperactive form of GNE/MNK.
It is not unlikely that treatments based on above concepts, which have failed to prove beneficial for other muscle wasting disorders, may prove beneficial for HIBM.
For HIBM it is not about FINDING a cure, yet FUNDING a cure. With additional funding and awareness, we can speed up the research significantly. ARM offers scientific grants to research centers who are interested in working towards developing a treatment for HIBM.
You can find a lot of information here on our website. If you would like to speak with a physician regarding HIBM, you may call (818) 789-1044.
This disorder was first called"Vacuolar Myopathy Sparing the Quadriceps" by Sadeh, et al, in a paper published in the medical journal, Brain, 1993 (116: pages 217-232). You may obtain a copy of this paper from any medical library.
If you are affected with another disorder, such as Multiple Sclerosis (MS), we recommend database at national organization of rare diseases for an organization that is focused on your disease. If you are affected with a more common disease such as MS, there is probably more than one organization to offer help and research funding.