Erythrocyte calcium transport in myotonic and facioscapulohumeral muscular dystrophy.

We studied calcium transport in inside-out erythrocyte vesicles from patients with myotonic or facioscapulohumeral dystrophy and age- and sex-matched controls. No significant difference was noted in the affinity of the transporter for calcium or the maximum reaction velocity. Under identical conditions, we previously found that Duchenne dystrophy membranes differed from controls in affinity for calcium and maximum velocity. The results reported here imply that the abnormality in Duchenne dystrophy is specific and not an abnormality found in all forms of dystrophy.