Phenotypes and genotypes in 2 DGI families with different DSPP mutations
Phenotypes and genotypes in 2 DGI families with different DSPP mutations
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2个具有不同DSPP突变的DGI家族的表型和基因型
DOI：
10.1016/j.tripleo.2005.06.020
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发表时间：
2006-09-01
期刊：
影响因子：
--
通讯作者：
Bian, Zhuan
中科院分区：
文献类型：
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作者：
Song, Yaling;Wang, Changning;Bian, Zhuan
Objective.本研究的目的是描述DSPP基因无义突变导致的牙本质超微结构特征，并定义与牙本质生成不全II型（DGI-II）家族中特定DSPP突变相关的各种表型。对两个DGI-II家系进行了表型和基因型调查。通过扩增DSPP外显子和测序产物进行突变分析。用扫描电镜和透射电镜观察与突变相关的牙本质超微结构。2个家系的患牙表现为牙齿变色、磨耗、髓室消失。第1家系的乳牙中也出现了“壳”齿表型。在DSPP中发现一个无义突变（c.133C -> T）和一个错义突变（c.52G -> T）。DSPP基因无义突变家系1的牙本质小管形态不规则，牙本质-牙釉质连接处光滑，有明显的缝隙，牙釉质结构异常，牙本质小管周围有大量的纤维束。我们报道了DSPP基因无义突变导致的牙齿超微结构特征，支持DSPP中c.133C -> T和c.52G -> T可能是2个突变热点。相同的DSPP突变可能导致多个不相关的DGI家族具有不同的临床表型。
Objective. The objective of this study was to characterize dentin ultrastructural features resulting from a nonsense mutation in DSPP gene and to define various phenotypes associated with specific DSPP mutations in families with Dentinogenesis Imperfecta type II (DGI-II).Study design. Two families with DGI-II were investigated for phenotypes and genotypes. Mutation analysis was performed by amplifying DSPP exons and sequencing the products. Dentin ultrastructure associated with the specific mutation was examined with scanning electronic microscopy and transmission electronic microscopy.Results. Teeth discoloration, attrition, and obliterated pulp chambers showed in affected members of 2 families. "Shell" teeth phenotypes were also presented in deciduous teeth of family 1. A nonsense mutation (c.133C -> T) in family I and a missense mutation (c.52G -> T) in family 2 were identified in DSPP. Irregular dentin tubules, smooth dentinoenamel junction with an obvious gap, abnormal enamel structure, and amounts of fibril bundles around dentin tubules were manifested in the specimen from family 1 with the nonsense mutation in DSPP.Conclusions. We reported characteristic tooth ultrastructure resulting from a nonsense mutation in DSPP gene and supported that the c.133C -> T and c.52G -> T in DSPP could be the 2 mutation hotspots. The same DSPP mutations may be causative for multiple unrelated DGI families with different clinical phenotypes.