Possible Evidence for a Variant of Myasthenia Gravis Based on HLA and Acetylcholine Receptor Antibody in Chinese Patients

SUMMARY A comprehensive study of 194 Chinese patients with myastheniagravis in Hong Kong has shown district differences from thepatterns of disease seen in Caucasians. Restricted ocular myastheniais the predominant disease type in patients presenting in thefirst two decades of life and is associated with absence orlow titres of acetylcholine receptor antibody. Predispositionto this type of disease is strongly associated with HLA-DRw9.Generalized myasthenia gravis occurs predominantly in patientspresenting after the age of 20 years and is accompanied by hightitres of acetylcholine receptor antibody but is less stronglyassociated with HLA-DRw9. It is suggested that myasthenia gravisoccurring within the first two decades of life and characterizedby affected ocular muscles and absence or low titre of acetycholinereceptor antibody is a genetically determined variant of thedisease which occurs commonly in Orientals.