From OMIMNonaka myopathy (NM) is an autosomal recessive progressive adult-onset myopathy with a predeliction for distal muscle involvement, usually affecting the lower limbs and resulting in gait abnormalities or loss of ambulation. Some individuals may have involvement of the upper limbs or proximal muscles (Argov et al., 2003). In rare cases (up to 2.5%), the myopathy can be associated with mild, asymptomatic thrombocytopenia, as observed in the allelic disorder THC12 (summary by Revel-Vilk et al., 2018).
Historically, the disorder has had several different names, including distal myopathy with rimmed vacuoles, inclusion body myopathy, and quadriceps-sparing myopathy. Huizing et al. (2014) proposed using the term 'GNE myopathy' to refer to this disorder.
http://www.omim.org/entry/605820 From MedlinePlus GeneticsGNE myopathy is a condition that primarily affects skeletal muscles, which are muscles that the body uses for movement. This disorder causes muscle weakness that appears in late adolescence or early adulthood and worsens over time.
Difficulty lifting the front part of the foot (foot drop) is often the first sign of GNE myopathy. For individuals with GNE myopathy, foot drop is caused by weakness of a muscle in the lower leg called the tibialis anterior. This muscle helps raise the foot up. Weakness in the tibialis anterior alters the way a person walks and makes it difficult to run and climb stairs. As the disorder progresses, weakness also develops in the muscles of the upper legs, hips, shoulders, and hands. Unlike most forms of myopathy, GNE myopathy usually does not affect the quadriceps, which are a group of large muscles at the front of the thigh. This condition also does not affect the muscles of the eye or heart, and it does not cause neurological problems. Weakness in leg muscles makes walking increasingly difficult, and most people with GNE myopathy require wheelchair assistance within 20 years after the signs and symptoms of the disorder appear.
People with the characteristic features of GNE myopathy have been described in several different populations. When the condition was first reported in Japanese families, researchers called it distal myopathy with rimmed vacuoles (DMRV) or Nonaka myopathy. When a similar disorder was discovered in Iranian Jewish families, researchers called it rimmed vacuole myopathy or hereditary inclusion body myopathy (HIBM). It has since become clear that these conditions are variations of a single disorder caused by changes in the same gene.
https://medlineplus.gov/genetics/condition/gne-myopathy