遗传性牙本质发育不全Ⅱ型DSPP基因新突变

Identification of two novel mutations of DSPP gene in dentinogenesis imperfecta type Ⅱ

目的分析我国遗传性牙本质发育不全Ⅱ型(dentinogenesisimperfectatypeⅡ,DGI-Ⅱ)患者DSPP基因突变特征,从分子水平探讨DGI-Ⅱ的发病机制。方法抽提2个汉族遗传性牙本质发育不全Ⅱ型家系患者外周静脉血基因组DNA,应用聚合酶链反应及DNA测序技术,结合序列分析方法,对2个家系共13名家庭成员的DSPP基因1～4号外显子及其邻近序列进行突变分析。结果家系A中的患者在DSPP的第4外显子发生Asn164Tyr突变;家系B的患者在DSPP第4外显子发生Cys159Trp突变。结论这两个突变系是国内外尚未报道的新突变。

Objective To investigate mutations of DSPP gene in dentinogenesis impeffecta type Ⅱ（DGI- Ⅱ ） to further illuminate the genetic basis of DGI- Ⅱ in China. Methods Polymerase chain reaction and DNA direct sequencing were employed to analyze exons 1-4 of DSPP and their flanking sequences in members of two Chinease families with DGI- Ⅱ . Results In family A, the affected individuals carry an A→T transversion at nt 6026. The affected individuals in family B carry a T→G transversion at nt 6013. Conclusion These are novel mutations. The results of this study expand the spectnnn of DSPP gene mutations associated with DGI- Ⅱ .