[Duchenne's muscular dystrophy: also in girls?]

Duchenne's muscular dystrophy is inherited as a recessive X-linked trait: Even-though it rarely appears in females it can be seen. We have examined 5 children of one family. Two boys and one girl showed typical symptoms and clinical as well as light- and electronmicroscopical findings of this disease. In order to understand the mode of the genetic pattern, we have analysed the chromosomes, proved the fatherhood and assured the increased Ca-pooling in non-necrotic muscle fibers; in vitro-examinations of the amino-acid-incorporation in ribosomes and of the synthesis of collagen in muscular cells were done as well. Evaluating all of the results, the inheritance must be X-linked recessive and the girl, with high incidence, is a so called "manifesting carrier". The explanation offers Lyons hypothesis, which suggests that in most of the girl's muscle cells the X-Chromosomes, inherited from the mother, are active and lead to the manifestation of the illness. Consequences in advising the family genetically must be taken.