HIBM (Hereditary Inclusion Body Myopathies) are a group of rare/orphan genetic disorders. HIBM causes progressive muscle wasting and weakness that begins in young adulthood and can lead to very severe disability within 10 - 20 years. Besides clusters of patients amongst people of Middle Eastern, Jewish, or Japanese heritage, patients can be found in every corner of the world. HIBM has been identified in people Asian (Japanese, Korean, Chinese and others), European, South American, African, and Middle Eastern (Muslim, Palestinian, Jewish, Iranian) origins.
HIBM is also known as Distal Myopathy with Rimmed Vacuoles (DMRV), Quadriceps Sparing Myopathy (QSM), or GNE related muscle disease. It 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 person's 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). It is caused by genetic variations in a gene known as GNE.