We describe a family an autosomal dominant myotonic myopathy with abse
nce of the abnormal CTG expansion characteristic of myotonic dystrophy
. We believe that the findings in this family concur with those of rec
ent case reports which have postulated the existence of a new adult on
set myotonic disorder, distinct from myotonic dystrophy: 'proximal myo
tonic myopathy'. (C) Harcourt Brace & Co. Ltd 1998.