摘要
目的用短串联重复序列－Ｄ２１Ｓ２１５和Ｄ２１Ｓ１２０的多态性诊断２１三体患者中２１号额外染色体的双亲起源。方法ＰＣＲ扩增上述两个短串联重复序列，对扩增产物进行聚丙烯酰胺凝胶电泳和硝酸银染色检测。根据患者及其父母基因型的比较来确定２１号额外染色体的双亲起源。结果在２４例２１三体患者中，１７例的２１号额外染色体的双亲来源被检测出，其中来自母亲和父亲的分别为１２例和５例。母亲来源组母亲的平均年龄明显高于父亲来源组母亲的年龄。结论根据这两个标记能确定２１三体患者中２１号额外染色体的双亲起源。
Objective To detect the parental origin of extra chromosome 21 in Down syndrome, using two (GT)n polymorphic markersD21S215 and D21S120.Methods The alleles of D21S215 and D21S120 were amplified by polymerase chain reaction and identified with denaturing polyacrylamide gel electrophoresis followed with Agstaining. The parental origin of extra chromosome 21 was determined by comparing genotypes of probands with their parents.Results The parental origin of extra chromosome 21 was determined in 17 Down syndrome out of 24, with 12 and 5 inherited from mother and father respectively. Conclusion The parental origin of extra chromosome 21 in Down syndrome can be determined by analyzing the polymorphisms of D21S215 and D21S120. Etiological study of trisomy 21 should be focused on maternal meiosis.
出处
《中华医学遗传学杂志》
CAS
CSCD
北大核心
1998年第4期206-209,共4页
Chinese Journal of Medical Genetics
