Central core disease and congenital neuromuscular disease with uniform type 1 fibers in one family

We report a family in which the father had central core disease and his son had congenital neuromuscular disease with uniform type 1 fibers. This is t he first report of such a combination. Although they had no recognized muta tion in the ryanodine receptor gene, it is highly likely that the son also had central core disease but without core structures. The absence of cores may be due to the muscle sample or the young age of the patient since core structures have been reported to increase with age. Although the prevalence of core structures in individual muscles is unknown, there is a possibilit y of sampling error. In some patients, congenital neuromuscular disease wit h uniform type 1 fibers is closely related to or identical with central cor e disease. (C) 2000 Published by Elsevier Science B.V. All rights reserved. .