遗传性牙龈纤维瘤病致病基因的排除性定位

目的:对我国现有的2例家族遗传性牙龈纤维瘤病进行国外已证实的已知基因突变位点--SOS1基因21号外显子的排除性定位。方法:采用PCR—SSCP-银染的方法对2例遗传性牙龈纤维瘤病家系的致病基因进行排除性定位。结果:两家系中均未发现SOS1基因的缺失。5％的聚丙烯酰胺凝胶电泳结果表明两家系中无典型临床表现者电泳条带无明显的异常，而有典型临床表现者发现家系1有4例患者的电泳条带有明显位移，条带离加样孔较正常对照近，家系2有2例患者的电泳条带有明显位移，但条带离加样孔较正常对照远。结论：两家系无典型临床表现者无SOS1基因的突变，有典型临床表现者存在有SOS1基因21号外显子的突变，但是，是否所有有典型临床症状的患者其基因突变的位置及涉及的碱基片段都相同还需进一步研究。

Exclusive Gene Location of Hereditary Gingival Fibromatosis

Objective: To exclude known gene mutation,21 exon of SOS1 which had been certified by foreign country ,form 2 families with hereditary gingival fibromatosis. Methods: Polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP) was used to exclude known gene mutation of HGF from 2 familial gingival fibromatosis. Result: It was not found the deletion of 21 exon of SOS1. PCR-SSCP showed no abnormality among family members without HGF symptoms. However,among family members with typical HGFsymptoms,there were 6 patients (family 1, 4 patients;family 2,2 patients)whose electrophoretic patten were abnormal. In addition ,their abnormalities were not absolutely identical. Conclusion: All members of 2 families without HGF were not found mutation of 21 exon of SOS1,but 6 persons among members with typical HGF symptoms were found mutation .however,whether all members with typical HGF symptoms have same gene mutation is still not clear.