牙本质发育不全Ⅱ型1例家系调查与遗传分析

Pedigree investigation and genetic analysis on a family with dentinogenesis imperfecta type Ⅱ

目的研究1例遗传性牙本质发育不全Ⅱ型(DGI-Ⅱ)家系致病基因是否与染色体4q21连锁,从分子水平探讨DGI-Ⅱ的发病机制。方法用FTA洗脱卡对遗传性牙本质发育不全Ⅱ型家系的6名成员进行末梢采血,提取纯化基因组DNA;选择染色体4q21上4个STR标记做荧光标记PCR扩增,分析致病基因与4个STR标记的连锁关系。结果得到6名家系成员的4个STR标记的基因型和单体型。结论 DGI-Ⅱ家系致病基因定位在染色体4q21上,以上4个STR标记可用于该家系DGI-Ⅱ的产前基因诊断。

Objective To investigate the linkage between dentinogenesis imperfecta type II(DGI-Ⅱ) and chromosome 4 q21 in a family with DGI-Ⅱ and further elucidate the molecular mechanism of DGI-Ⅱ. Methods Peripheral blood samples were collected by FTA elute cards from six members of a family with DGI-Ⅱ;and genomic DNA was extracted from these samples and amplified with 4 STR markers(D4S451, DSSP, DMP1 and D4S1563) using fluorescence-based PCR;genetic linkage analysis between 4 STR markers on chromosome 4q21 and DGI-Ⅱ. Results Genotype and haplotype were acquired in 6 family members, respectively. Conclusion The locus of DGI-II is located on human chromosome 4 q21, which suggests that the 4 STR markers can be used for prenatal genetic diagnosis on DGI-II of this family.