Familial multicore disease with focal loss of cross-striations and ophthalmoplegia.

Two brother are described with a congenital myopathy, including weakness of the external ocular muscles, whose biopsies showed multicores and focal loss of cross-striations, with failure of fibre type differentiation. In one patient changes in distribution and size of these core-like structures were observed in a second biopsy taken 5 years later. This family, together with others previously reported, may represent a genetically distinct subgroup of congenital multicore disease.