一个遗传性乳光牙本质家系致病基因的初步定位

Chromosome localization of the dentinogenesis imperfecta type Ⅱ locus

目的 研究遗传性乳光牙本质家系致病基因是否与染色体 4q2 1连锁。方法 提取在天津塘沽地区发现的一个遗传性乳光牙本质家系成员的外周血 DNA,选择染色体 4q2 1上的 4个短串联重复序列多态性标记 (short tandem repeatpolymorphism,STRP) :GATA6 2 A11、DSP(P)、SPP1和 D4S15 6 3做荧光标记 PCR、等位片段分析 ,用 L od连锁分析法分析该家系致病基因位点与上述 4个 STR的连锁关系。结果分别得到 13个家庭成员上述 4个位点的基因型和单体型。ML INK软件分析显示 :GATA6 2 A11、DSP(P)与致病基因位点连锁的最大 L od值分别为 1.6 3(θ=0 )和 1.6 8(θ=0 )。结论 遗传性乳光牙本质家系的致病基因初步定位在

Objective To scrutinize the linkage between dentinogenesis imperfecta type Ⅱ and chromosome 4q21 in a Tianjin Tanggu family. Methods Blood samples were collected from 13 members of the family. DNA was analyzed with 4 short tandem repeat polymorphisms markers [GATA62A11, DSP(P), SPP1 and D4S1563] using fluorescence based PCR. The linkage between four markers on chromosome 4q21 and dentinogenesis imperfecta type Ⅱ was tested by Lod score analysis. Results GATA62A11 and DSP(P) suggested linkage and yielded a Lod score of 1.63 at θ=0, and 1.68 at θ=0 by means of the MLINK software, respectively. Genotype and haplotype were acquired. Conclusion The disease gene of the dentinogenesis imperfecta type Ⅱ family is located on chromosome 4q. The result will be helpful for the further identification of the dentinogenesis imperfecta type Ⅱ gene.