染色体平衡易位遗传效应的相关研究

目的研究染色体平衡易位的遗传效应。方法应用外周血淋巴细胞培养、染色体显带技术进行核型分析，通过遗传咨询进行跟踪随访。结果在4498例外周血检查对象中，发现52个染色体平衡易位家系、68例染色体平衡易位个体，检出率1．51％，其中相互易位40个家系54例，罗伯逊易位12个家系14例，检出率分别为1．20％和0．31％。平衡易位涉及两条常染色体间与X染色体和多条染色体间相互易位。有异常表型者13例，占19．12％，表现为生长发育落后、智力低下及各种先天异常。结论部分染色体平衡易位个体有异常表型伴智力低下，对智力低下患者可作染色体核型分析。复杂型易位表型异常风险随断裂点数目增加而增高，自发性流产率及生育畸形儿的风险也随之增高。

Study on Genetic Effect of Balanced Chromosomal Translocation

ObjectiveTo study the genetic effect of balanced chromosomal translocation.MethodsChromosomal analysis by using cytogenetic banding techniques with lymphocytes of peripheral blood, together with genetic consultation.ResultsFifty-two balanced chromosomal translocation families and 68 individuals were detected (54 cases of 40 reciprocal translocation pedigrees and 14 cases of 12 Robertsonian translocation pedigrees) among 4 498 cases. The detection rate of balanced translocation was 1.51%.It included translocations between 2 autosomal chromosomes and between an autosomal chromosome and a X chromosome, and complex reciprocal translocation. Thirteen cases had abnormal phenotypes in 68 balanced individuals. The positive rate was 19.12%. The individuals of balanced translocation suffered from developmental retardation, mental retardation and multiple congenital malformations.ConclusionA portion of the balanced chromosomal translocation individuals have abnormal phenotypes with mental retardation. Complex translocation associated with abnormal phenotypes increases with the number of breakpoints. It is also in the incidence of spontaneous abortions and malformed offsping.