[Haplotype and linkage analysis in Chinese hereditary mixed polyposis syndrome]

To investigate if hereditary mixed polyposis syndrome (HMPS) locus of two Singapore Chinese HMPS families is identical with the Ashkenazi families.

Genomic DNA was extracted, multiplex polymerase chain reaction (PCR) was used to amplify 4 microsatellite markers D15S1010, D15S1007, ACTC and D15S118 in 31 individuals from two families. The HMPS locus cosecretion of the markers on 15q13 over a region of 2.8 cM was confirmed by Haplotype and linkage analysis.

The disease of haplotype identified in one pedigree was not co-segregated with an affected individual while no definitive disease haplotype could be assigned for the second pedigree. The maximum two-point and multi-point LOD scores at ACTC for the two Chinese families are 0.20 (theta = 0.3) and -5.0 respectively.

Haplotype and linkage analysis indicate that the Ashkenazi haplotypes is not associated with HMPS in Singapore Chinese families, which suggests genetic heterogeneity.