Charlwood J, Clayton P, Keir G, Mian N, Young E, Winchester B
Biochemistry Unit, Institute of Child Health, London, U.K.
Prenat Diagn. 1998 Jul;18(7):693-9.
Two pregnancies at risk for the carbohydrate-deficient glycoprotein syndrome Type 1A (CDG1A, phosphomannomutase deficient) were monitored by enzyme and genetic linkage analyses. The index case in both families had a proven deficiency of phosphomannomutase (PMM). An unaffected fetus was predicted in family 1 following amniocentesis. Normal PMM activity was found in cultured amniotic fluid cells and there was no elevation of lysosomal enzymes in the amniotic fluid. Genetic linkage analysis using microsatellite markers closely linked to the CDG1A gene confirmed this prediction. A healthy child was born. In the second family direct assay of chorionic villi showed a profound deficiency of PMM and genetic linkage analysis showed the fetus to have the same haplotype as the proband. The pregnancy was terminated and a deficiency of PMM was confirmed in cultured fibroblasts from the fetus. Reliable prenatal diagnosis of CDG Type 1A (PMM-deficient) can be achieved by a combination of biochemical and molecular genetic tests.
通过酶学和基因连锁分析对两例有1A型糖蛋白缺乏综合征（CDG1A，磷酸甘露糖变位酶缺乏）风险的妊娠进行了监测。两个家系中的先证者均已证实存在磷酸甘露糖变位酶（PMM）缺乏。在第一个家系中，羊膜腔穿刺术后预测胎儿未受影响。在培养的羊水细胞中发现PMM活性正常，羊水中溶酶体酶未升高。使用与CDG1A基因紧密连锁的微卫星标记进行的基因连锁分析证实了这一预测。一名健康婴儿出生。在第二个家系中，对绒毛膜绒毛的直接检测显示PMM严重缺乏，基因连锁分析显示胎儿与先证者具有相同的单倍型。妊娠终止，在胎儿培养的成纤维细胞中证实存在PMM缺乏。通过生化和分子遗传学检测相结合，可以实现对1A型CDG（PMM缺乏型）可靠的产前诊断。
