McKinley M J, Kearney L U, Nicolaides K H, Gosden C M, Webb T P, Fryns J P
Harris Birthright Research Centre for Fetal Medicine, London, England.
Am J Med Genet. 1988 May-Jun;30(1-2):355-68. doi: 10.1002/ajmg.1320300136.
Second trimester ultrasound-guided fetal blood sampling and placental biopsy were performed on 10 pregnancies at risk for fra(X)-linked mental retardation (Martin-Bell syndrome). Three cases were diagnosed as affected after cytogenetic analysis of fetal blood and placental cultures. The fra(X)(q27.3) and common fragile sites were shown to be expressed at a lower level in placenta than in fetal blood. Induction methods included methotrexate, 5-fluoro-2-deoxyuridine, and excess thymidine. Excess thymidine may give the best expression of fra(X)(q27.3). Enhancement of fra(X)(q27.3) expression was not shown with caffeine or 5-methoxybenzamide.
对10例有脆性X连锁智力迟钝（马丁-贝尔综合征）风险的妊娠进行了孕中期超声引导下的胎儿采血和胎盘活检。对胎儿血液和胎盘培养物进行细胞遗传学分析后，3例被诊断为患病。结果显示，脆性X（q27.3）和常见脆性位点在胎盘中的表达水平低于胎儿血液。诱导方法包括甲氨蝶呤、5-氟-2-脱氧尿苷和过量胸苷。过量胸苷可能使脆性X（q27.3）得到最佳表达。咖啡因或5-甲氧基苯甲酰胺未显示出对脆性X（q27.3）表达的增强作用。
