NO EVIDENCE FOR AN ASSOCIATION OF ACHR BETA-SUBUNIT GENE (CHRNB1) WITH MYASTHENIA-GRAVIS

Using a polymorphic dinucleotide repeat, we have investigated the cont ribution of the gene encoding the beta-subunit of the muscle acetylcho line receptor (CHRNB1), the target autoantigen, to the susceptibility to myasthenia gravis (MG), We have combined a case-control study (comp aring 143 patients and 162 controls) and a transmission-disequilibrium test bearing on 35 simplex families with heterozygous parents. There was no evidence for an association of CHRNB1 with MG, even after subgr ouping patients according to thymus histology, or other clinical crite ria. Interestingly however, the shortest four variants of the CHRNB1 m icrosatellite were seen only in patients with thymus hyperplasia and i n none of the control subjects (P < 0.0025). (C) 1997 Elsevier Science B.V.