Abstract: Objective To refine the Marie Unna hereditary hypotrichosis (MUHH) locus to a narrow chromosome region and to make the gene cloning feasible. Methods Genotyping and linkage analysis were performed in two multi-generation Chinese families with high-density microsatellite markers spanning the previously mapped interval at 8p21. Results In pedigree 1, significant evidence for linkage was observed in this region with a maximum two-point lod score of 3.01 (θ=0). Haplotype analysis localized the MUHH locus within the region defined by D8S282 and D8S1839. But the linkage between the MUHH phenotype and the locus at 8p21 was excluded in the other family. Conclusion This study provides the evidence of genetic heterogeneity in MUHH.

Key words: Hypolriehosis, Linkage (Genelics), Haploicly, Genetic heleiogeneity