Southern印迹检测智力低下患者的脆性X基因

目的用Southern印迹法检测脆性X基因来确定脆性X基因携带者和脆性X综合征的患者。方法提取27例智力低下患者标本的DNA,用EagI和EcoRI酶切,酶切产物电泳后进行Southern转印,探针杂交后放射自显影,根据DNA片段大小检测脆性X综合征携带者与突变患者。结果检测24位智力低下患者的外周血及3例有智力低下家族史孕妇的羊水后发现3例患者患有脆性X综合征。结论用Southern印迹法诊断脆性X综合征,是一种可靠的首选检测方法,适用于出生后患儿及产前诊断及遗传咨询。

Detection of fragile x gene by Southern blotting in patients with mental retardation

Objective To investigate full mutation and premutation of fragile X gene in patients with mental retardation by Southern blotting.Methods The genomic DNA in blood samples extracted from 27 patients with mental retardation was digested by EagI and EcoRI.Following electrophoresis the digested products were detected by Southern blotting.By analyzing the results,the subjects with normal genotype,the carrier of fragile X gene and the patients with full mutation were distinguished.Results Three cases of Fra (X) syndrome were found in 27 samples in which 24 peripheral blood samples were from the patients with mental retardation and 3 amniotic fluid samples were from gravida with family history of mental retardation.Conclusion Southern blotting is an efficient and reliable test which is the priority choice for the diagnosis of fragile X syndrome after birth,as well as its prenatal diagnosis and genetic counseling.