Cataract and gamma-glutamyl cycle in myotonic dystrophy.

Gamma-Glutamyl transpeptidase (gamma-GT) may be responsible for the rapid catabolism and low levels of lenticular glutathione often associated with cataract formation. Elevated levels of serum gamma-GT in patients with myotonic dystrophy suggest that since the defect could be present in all tissues it might be responsible for the cataracts frequently observed in this genetic disease.