RESUMO
The present study included muscle biopsies from 12 infants [5 females and 7 males] with Werding-Hoffman disease [WHD]. The mean age of presentation was 11.8 months. History of consanguinity was detected in [7/12] of cases. The infants were presented with a history of typical floppy baby pattern since birth or early in the first few months of life. The presence of large groups of atrophied small muscle fibers and large hypertrophied muscle fibers is the classical microscopic picture. The enzyme histochemistry showed that the atrophied and the hypertrophied muscle fibers are of type I and type II. The electron microscopy showed disorganized Z bands in the atrophied muscle fibers. The diagnosis of WHD needs correlation of the clinical picture, serum creatine phosphokinase, the electromyography, the light microscopy, enzyme histochemistry and the electron microscopy