Coincidence of neurofibromatosis and myotonic dystrophy in a kindred

Abstract

Neurofibromatosis and myotonic dystrophy have occurred in 10 members of a nonconsanguineous family with a high degree of concordance. The expression of neurofibromatosis is peripheral, and the expression of myotonic dystrophy has produced at least moderately severe disability. Neither disease has appeared to alter the phenotypic expression of the other when both have occurred simultaneously. Secretor typing supports the assumption that the myotonic dystrophy in this family is the commonly recognised secretor-linked entity. The segregation pattern of the 2 disorders in this family suggests the possibility of close linkage between the loci for neurofibromatosis and myotonic dystrophy.