Rapid Gene Diagnosis Of Down Syndrome By Quantitative Polymerase Chain Reaction

Objective: Exploring the possibility of gene diagnosis for Down syndrome by means of molecular biological techniques and developing a rapid, simple and accurate gene diagnosis technique for Down syndrome. Methods: 4 short tandem repeats(STRs) loci (D21S11, D21S1411, D21S1412, D21S1414) in and near the core region (21 q-21 q)on 21 chromosome of blooding samples from 8 normal people, 11 cases of Down syndrome and 1 case of fetus umbilical core were analyzed and detected by polymerase chain reaction, non-degeneration polyacrylamide gel electrophories, silver staining and electrophoresis band DNA content scanning. Results: ?/8,7/8,3/8,7/8 of normal people showed two bands with a DNA content ratio of 1:1 and 2/8, 1/8,5/8, 1/8 of normal people showed one band in 4 loci, respectively .(2)7/11, 8/11, 6/11,7/11 of all patients showed two bands with a DNA content ratio of 2:1; 3/11,2/11,2/11,3/11 showed three bands with a DNA content ratio of 1:1:1 and 1/11, 1/11, 3/11,1/11 showed one band. The blooding sample of fetus showed two bands with a DNA content ratio of 2:1 at 3 loci and showed one hand at 1 locus. (3)11 patients and the fetus werediagnosed as Down syndrome. All the results were consistent with the results of cytogenetics. Conclusion: The 4 selected loci have high polymorphism and they can provide much polymorphotic information. About 91. 7%, 91.7%,75%,91.7% patients were detected correctly with D21S11, D21S1411, D21S1412, D21S1414, respectively. All patients were detected correctly by combining with 4 loci. Making use of this method, Down syndrome can be diagnosed rapidly and accurately within 24 hours. The 4 loci are valuable gene markers for gene diagnosis of Down syndrome. The operation is simple, rapid, and the results are accurate. This method has high clinical value.Liu Xuexia(Genetics) Directed by Wang Xiuhai Wang Pei1in...