Two cases with congenital fibre type disproportion are presented. The cases are unusual in that there were significant dysmorphic features in case 1, and both cases showed electromyographic abnormalities suggestive of denervation. A third case, the father of the second patient, showed clinical features of congenital fibre type disproportion in early life but later developed the rigid spine syndrome. The spinal cord of case 3 showed atrophy and degeneration of medial neuronal group in the lumbosacral segments. The clinical and pathological features in these cases further extend the view that congenital fibre type disproportion may be seen in a variety of patients.