摘要目的 报道1例雀斑及其三代家系,并对其致病基因进行遗传连锁分析.方法 选取位于4q和1号染色体的微卫星标记对该家系进行致病基因定位研究,用ABI3730测序仪进行微卫星标记的基因分型,利用Linkage软件(5.10 Version)和Cyrillic软件(2.01 Version)进行连锁和单倍型分析.结果 该家系在常染色体显性遗传模式下,外显率为99.9%时,排除该家系与4号染色体的连锁,在1号染色体上的微卫星标记D1S2635和D1S2844处获得可能连锁的证据,最大LOD值为1.50(重组率0=0.00).单倍型分析将该家系可能的致病基因定位在微卫星标记DIS2624和D1S2799之间12 Mb区域内.结论 雀斑存在遗传异质性.在该家系中,本病可能的致病基因存在于染色体1q22-q24的21.2 cM区域内.

abstractsObjective 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 of99.9% 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.