Table 2 Hereditary inclusion body myopathy subtypes (further detailed by Needham et al.[29])
From: Sporadic inclusion body myositis: the genetic contributions to the pathogenesis
Hereditary IBM (hIBM) subtypes | OMIM# | Disease inheritance | Genes | Function of coding proteins |
|---|---|---|---|---|
Inclusion body myopathy 2 - hIBM2 (distal myopathy with rimmed vacuoles -DMRV/Nonaka myopathy) | 600737 (605820) | Autosomal-recessive | UDP-N-acetylgucosamine-2-epimerase/N-acetylmannosamine kinase (GNE) gene | A rate-limiting enzyme in the sialic acid biosynthetic pathway, involved in sialylation of muscle glycoproteins, and cellular homeostasis |
A leukoencephalopathy and a vacuolar myopathy resembling IBM | n/a | Autosomal-recessive | Laminin alpha 2 (LAMA2) gene[30] | An extracellular protein of basement membrane, mediates the attachment, migration, and organization of cells into tissues during embryonic development |
hIBM with congenital joint contractures, ophthalmoplegia and rimmed vacuoles – hIBM3 | 605637 | Autosomal-dominant | Myosin heavy chain IIa (MYH2; previously known as MHCIIa) gene | A member of Class II or conventional myosin heavy chains, functions in skeletal muscle contraction |
Inclusion body myopathy with early-onset Paget’s disease of the bone (PDB) and frontotemporal dementia (FTD) (IBMPFD) | 167320 | Autosomal-dominant | Valosin-containing protein (VCP) gene | A member of the ‘ATPases associated with a variety of activities (AAA-ATPase)’ superfamily, is involved in a variety of cellular activities, such as cell cycle control, membrane fusion and the ubiquitin-proteasome degradation pathway |