One autosomal recessive form of HIBM is known as IBM2 or GNE myopathy, which is a common genetic disorder amongst people of Iranian Jewish descent.
[1] IBM2 has also been identified in other minorities throughout the world, including those of Asian, European, and South American, and Middle Eastern descent.
Another protein, neural cell adhesion molecule is under-sialyated in people with IBM, but as of 2016 it had no known role in muscle function.
If the quadriceps are spared but the hamstrings and iliopsoas are severely affected in a person between ages of 20 - 40, it is very likely HIBM will be at the top of the differential diagnosis.
A 2009 review noted that muscle weakness usually begins after age 20 and after 20–30 years, the person usually requires a wheelchair for mobility.
[2] Hereditary inclusion body myopathy (IBM) constitutes a unique group of neuromuscular disorders characterized by adult-onset slowly progressive distal and proximal weakness, and a typical muscle pathology including rimmed vacuoles and filamentous inclusions.
[15] Affected individuals in families of other ethnic origins were found to be compound heterozygotes for other distinct mutations in the GNE gene.