Is central core disease with structural core a fetal defect?

Morphological and biochemical studies were performed in three cases of congenital non-progressive myopathy in two generations of the same family. In the muscle biopsy nearly all the fibres were uniform in enzyme activity and belonged to type 2 C. Typical structural central cores were observed in 90% of the muscle fibres. Some ultrastructural characteristics of the core area, as well as disturbances of the myofibrillar proteins pattern, seen in the examined cases suggest that core formation may be a result of protein synthesis disturbances in an early stage of myogenesis.