Hereditary Inclusion Body Myopathy - Classification

Classification

Types of hereditary inclusion body myopathy:

1. An autosomal dominant form (IBM1) where the quadriceps are one of the first muscles to become weak. Needham (2007) lists IBM1 under OMIM 601419:
2. An autosomal recessive form (IBM2), common among people of Middle Eastern and Jewish heritage. This form mainly affects leg muscles, but with an unusual distribution that spares the quadriceps: a so-called quadriceps-sparing myopathy (QSM), the quadriceps are among the last muscles to become weak. See: OMIM # 600737. Also see OMIM:605820(DMRV).
3. Nonaka distal myopathy with rimmed vacuoles, essentially a form of IBM2. See: OMIM # 605820:
4. Inclusion body myopathy associated with Paget disease of bone and frontotemporal dementia (IBMPFD), is linked to a slightly different gene on chromosome 9 (located at 9p13-p12). See: OMIM # 167320
5. Inclusion body myopathy-3 (IBM3) is linked to mutations in a gene encoding myosin heavy chain II proteins on chromosome 17 (located at 17p13.1). See: OMIM # 605637

More types of HIMBs, linked to other genes, may be identified in the future.