Duchenne Muscular Dystrophy Manifesting Carriers

To the Editor. —The article by Barkhaus and Gilchrist in the June 1989 issue of the Archives1 makes the appropriate point that Duchenne dystrophy in manifesting female carriers may be difficult to distinguish clinically from sporadic autosomal recessive limb-girdle muscular dystrophy. Limb-girdle muscular dystrophy is a heterogeneous syndrome, however, and autosomal dominant forms should also be considered in the differential diagnosis of females with this phenotype.2 If the family history is negative or ambiguous in patients with limb-girdle muscular dystrophy, then autosomal recessive inheritance is most likely, but an autosomal dominant form could not be ruled out by examination findings alone.2 In addition, autosomal dominant limb-girdle dystrophy transmitted from mother to daughter could clinically resemble the Duchenne carrier state.3 Distinction of Duchenne dystrophy from autosomal recessive or dominant muscular dystrophy in such patients is important for accurate genetic counseling. Genetic implications of the diagnosis of muscular