Alternative titles; symbols
SNOMEDCT: 26889001; ICD10CM: G72.49, M60, M60.9; DO: 633;
Lewkonia and Buxton (1973) described myositis in father and daughter. The daughter's illness resembled childhood dermatomyositis and progressed to systemic involvement with death less than 4 years after onset. The father's illness followed the course of adult polymyositis, with little evidence of systemic involvement. Proximal muscle weakness was a conspicuous feature in both. In both, the diagnosis of myositis was confirmed by muscle biopsy. The significance of the familial occurrence may be similar to that of familial SLE (152700) and familial autoimmune disorders (109100).
Rider et al. (1998) described the clinical, serologic, and immunogenetic features of idiopathic inflammatory myopathy (IIM), observed in 16 unrelated families in which 2 or more blood relatives developed the disorder. In addition, findings in patients with familial IIM were compared with those in 181 patients with sporadic IIM. Families included 3 pairs of monozygotic twins with juvenile dermatomyositis, 11 families with other sibs or relatives with polymyositis or dermatomyositis, and 2 families with inclusion body myositis (147421). They found that the clinical features of familial IIM were similar to those of sporadic IIM, although the frequency of myositis-specific autoantibodies was lower in familial than in sporadic cases. In the HLA system, DRB1*0301 was a common genetic risk factor for familial and sporadic IIM, but contributed less to the genetic risk of familial IIM. Homozygosity at the HLA-DQA1 locus was found to be a genetic risk factor unique to familial IIM. Rider et al. (1998) concluded that familial muscle weakness is not always due to inherited metabolic defects or dystrophies, but may be the result of the development of IIM in several members of the same family, and that multiple genetic factors are probably important in the etiology and disease expression of familial IIM, with DQA1 homozygosity being a distinct risk factor for familial IIM.
Lewkonia, R. M., Buxton, P. H. Myositis in father and daughter. J. Neurosurg. Psychiat. 36: 820-825, 1973.
Rider, L. G., Gurley, R. C., Pandey, J. P., Garcia-de la Torre, I., Kalovidouris, A. E., O'Hanlon, T. P., Love, L. A., Hennekam, R. C. M., Baumbach, L. L., Neville, H. E., Garcia, C. A., Klingman, J., Gibbs, M., Weisman, M. H., Targoff, I. N., Miller, F. W. Clinical, serologic, and immunogenetic features of familial idiopathic inflammatory myopathy. Arthritis Rheum. 41: 710-719, 1998. [PubMed: 9550481] [Full Text: https://doi.org/10.1002/1529-0131(199804)41:4<710::AID-ART19>3.0.CO;2-K]