Familial autoimmune myasthenia gravis.

Familial Autoimmune Myasthenia Gravis (FAMG) is rarely reported. We present a mother and son with late-onset mild to moderate ocular disease, low acetylcholine receptor antibody titre and the absence of a thymoma. Both responded well to low doses of anticholinesterase. HLA typing revealed that they did not share the usual HLA antigens or haplotypes with that previously reported in Caucasian and Chinese sporadic Myasthenia Gravis. Chinese FAMG may be associated with HLA antigens different from that of sporadic MG.