The success of SNP-based linkage disequilibrium (LD) mapping may depend on the extent of LD between adjacent markers, but little is known about the extent of inter-marker LD in non-isolated human populations. As a preliminary to SNP-based studies, we have physically mapped 13 chromosome 18q microsatellite markers on the TNG radiation hybrid panel at mean intervals of 237 kb. These markers were genotyped in a set of 58 European-American pedigrees collected for a linkage study of bipolar disorder. Genotypes were generated using semi-automated fluorescent methods and assembled into haplotypes. Haplotype data was analyzed for inter-marker LD in the unrelated probands using a Monte Carlo permutation of the Fisher Exact Test. Significant LD was observed for 5 out of the 11 adjacent marker pairs. There was also a significant relationship between the magnitude of LD and physical distance. Detectable LD was observed over a physical distance up to ∼ 400 kb. These results demonstrate that linkage disequilibrium can be detected over relatively large physical distances on chromosome 18q in European Americans with bipolar disorder.
|Original language||English (US)|
|Number of pages||1|
|Journal||American Journal of Medical Genetics - Neuropsychiatric Genetics|
|State||Published - Aug 7 2000|
ASJC Scopus subject areas
- Psychiatry and Mental health
- Cellular and Molecular Neuroscience