Eye movement disorder: an early expression of the myotonic dystrophy gene?

Eye movement recording (EMR) has been performed in 5 asymptomatic myotonic dystrophy (MyD) gene carriers, 7 mildly affected MyD patients, and 23 age- and sex-matched healthy controls. The purpose of the study was to evaluate whether eye movement abnormalities are an early expression of the MyD gene, and to determine the value of this procedure for detection of otherwise asymptomatic gene carriers. EMR did not reveal any abnormalities in the asymptomatic group, but in the mildly affected group showed significantly (P less than 0.01) decreased maximum velocities of the saccades, compared with controls. The results indicate that EMR may aid in the detection of mildly affected MyD patients. However, true presymptomatic diagnosis with EMR has not yet proven possible.