Chinese Journal of Dermatology ›› 2008, Vol. 41 ›› Issue (4): 251-253.

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  • Received:2007-03-12 Revised:2007-05-28 Online:2008-04-15 Published:2008-04-15

Abstract: Objective To report a three-generation Chinese family with freckle and to make a genetic linkage analysis in this family. Methods Genetic linkage analysis was carried out in this family using microsatellite markers distributed over chromosome 4q and 1. Two-point logarithm of odds (LOD) scores were calculated using the Linkage program package (version 5.1), and haplotype was analyzed with Cyrillic version 2.01 software. Results Freckle was inherited in an autosomal dominant pattern with a penetrance of 99.9% in this family; linkage to chromosome 4q was ruled out however, supportive evidence was obtained for linkage to microsatellite markers D1S2635 and D1S2844 in chromosome 1q with a maximum LOD score of 1.50. Haplotype analysis in this family localized the locus of freckle to a 12 Mb region flanked by D1S2624 and D1S2799. Conclusions Freckle is a genetically heterogeneous disorder. The causative gene may be located in a 21.2 cM region on chromosome 1q22-24.