Segregation of Hla Haplotypes in 100 Families With a Myasthenia Gravis Patient

An analysis of the HLA data of 100 myasthenia gravis (MG) patients and their first degree relatives and spouses is presented. The family studies confirmed the excess of B8 in the myasthenia gravis patients and showed that the excess was not limited to the A1, B8 haplotype. An excess of B8 homozygous patients was found from the matings of two B8 heterozygous parents, suggesting the existence of a dominant B8 linked MG susceptibility. B8 homozygous individuals run a 4-7 times higher risk of acquiring myasthenia gravis than B8 heterozygous individuals.