Genetic susceptibility to multiple sclerosis in the Shanghai Chinese is not linked to the myelin basic protein gene microsatellite.

Aim-To investigate the role of myelin basic protein (MBP) gene polymorphisms in determining susceptibility to multiple sclerosis in a Shanghai Chinese population.Methods-Forty seven unrelated patients with multiple sclerosis and 94 healthy control subjects were included in the study. Genomic DNA was extracted from peripheral blood lymphocytes and amplified using the polymerase chain reaction to characterise two adjacent tetranucleotide repeats ([ATGG](12) and [TGGA](9)) located 5' to exon 1 of the MBP gene.Results-Two polymorphic loci were identified: locus A, comprising both repeats, and locus B, comprising the [ATGG](12) repeat only. Nine allelic variants were identified at locus A and six at locus B, ranging from 212 to 244 and 122 to 146 base pairs, respectively. The 244 base pair allele at locus A has not been reported before. The allele frequencies observed in the controls differed from those seen in normal white populations.Conclusions-The present study demonstrates a race specific pattern of allelic distribution within the tetranucleotide repeat of the MBP gene. Further studies are needed to fully elucidate the role of the MBP gene in inherited susceptibility to multiple sclerosis.