[The human major histocompatibility complex region is not a major susceptibility locus for Graves disease among the Hans in north of China].

OBJECTIVE

To determine if the human major histocompatibility complex (MHC) region located on chromosome 6 p21 is a major susceptibility locus for Graves' disease (GD) among the Hans in North of China.

METHODS

Four highly polymorphic microsatellite markers spanning the entire region of chromosome 6 p21 were employed to screen the DNA from blood samples of 54 Han multiplex families with GD (322 individuals) in Liaoning Province, northeast China. Tow-point and multi-point Lod scores were calculated under different levels of penetrance, assuming both dominant and recessive models. Multipoint nonparametric linkage (NPL) scores were also calculated.

RESULTS

The two-point Lod scores (theta = 0) and multipoint Lod scores for the 4 microsatellites were all less than -2 for all the markers tested, at all levels of penetrance, and in both the dominant and recessive modes of inheritance. No family showed a two-point Lod score or a multipoint Lod score of 1.0 or even larger under the assumed inheritance models. The maximum multipoint Lod score was 0.55 under the assumption of genetic heterogeneity, with the proportion of linked families of 29%. P values of greater than 0.05 were observed for all the multipoint NPL scores obtained.

CONCLUSION

No locus linked with GD among the Hans in North of China exists on chromosome 6 p21. Human MHC region is not a major susceptibility locus for northern Chinese Han Graves' disease.