Abstract：
The present study aims to investigate the mutation in a Chinese family with dentin dysplasia type II (DD-II) and to summarize mutation hotspots, clinical manifestations, and disease management strategies. Phenotype analysis, clinical intervention, mutation screening, and cosegregation analysis within the enrolled family were performed. A summary of the reported mutations in the dentin phosphoprotein (DPP) region of dentin sialophosphoprotein (DSPP) was analyzed. Pathogenicity prediction analysis of the physical properties and function of DSPP variants was performed by bioinformatic processing. Clinical management strategies are discussed. A novel pathogenic mutation (c.2035delA) in the DPP region of DSPP was identified, which was cosegregated in the family. The immature permanent teeth of patients with DD-II presented with X-shaped root canal phenotypes. Most of the identified mutations for DD-II were clustered in the DPP region between nucleotides 1686-2134. Points of differential diagnosis, clinical interventions, and management strategies are proposed. This study revealed a novel DSPP frameshift mutation and presented new clinical features of DD-II. The locus involving nucleotides 1686-2134 of DSPP may represent a mutational hotspot for the disease. Appropriate management of DD-II at different stages is important to avoid the development of secondary dental lesions.
摘要：
目的：研究一个中国牙本质发育不良II型（DD-II）家庭的突变，并总结突变热点，临床表现，和疾病管理策略。
方法：表型分析，临床干预,突变筛选,并在登记家庭内进行了共隔离分析。分析了牙本质唾液酸磷蛋白（DSPP）的牙本质磷蛋白（DPP）区域中报道的突变的摘要。通过生物信息学处理对DSPP变体的物理性质和功能进行致病性预测分析。讨论了临床管理策略。
结果：在DSPP的DPP区发现了一个新的致病突变（c.2050delA），这是家庭中的共同隔离。DD-II患者的未成熟恒牙表现为X形根管表型。大多数鉴定的DD-II突变聚集在核苷酸1686-2134之间的DPP区中。鉴别诊断要点，临床干预措施，并提出了管理策略。
结论：这项研究揭示了一种新的DSPP移码突变，并提出了DD-II的新临床特征。涉及DSPP的核苷酸1686-2134的基因座可能代表该疾病的突变热点。在不同阶段对DD-II进行适当的管理对于避免继发性牙病的发展很重要。
方法：表型分析，临床干预,突变筛选,并在登记家庭内进行了共隔离分析。分析了牙本质唾液酸磷蛋白（DSPP）的牙本质磷蛋白（DPP）区域中报道的突变的摘要。通过生物信息学处理对DSPP变体的物理性质和功能进行致病性预测分析。讨论了临床管理策略。
结果：在DSPP的DPP区发现了一个新的致病突变（c.2050delA），这是家庭中的共同隔离。DD-II患者的未成熟恒牙表现为X形根管表型。大多数鉴定的DD-II突变聚集在核苷酸1686-2134之间的DPP区中。鉴别诊断要点，临床干预措施，并提出了管理策略。
结论：这项研究揭示了一种新的DSPP移码突变，并提出了DD-II的新临床特征。涉及DSPP的核苷酸1686-2134的基因座可能代表该疾病的突变热点。在不同阶段对DD-II进行适当的管理对于避免继发性牙病的发展很重要。
