Fibre type disproportion in the rigid spine syndrome

An adolescent presented with the clinical symptomatology of the rigid spine syndrome. Whereas an earlier biopsy from the M. erector trunci showed myopathic features and marked endomysial fibrosis, recent findings in the M. biceps consisted of type I-fibre atrophy, type I-fibre predominance, and hypertrophy of type II-fibres. The significance of these findings and possibly a relationship to congenital fibre type disproportion are discussed.