6-丙酮酰四氢蝶呤合成酶缺乏的产前诊断

Prenatal diagnosis to 6-pyruvoyl tetrahydropterin synthase deficiency

目的对4个6-丙酮酰-四氢蝶呤合成酶(PTPS)缺陷所致非经典型苯酮尿症家系第二胎胎儿进行产前DNA突变分析以确诊其是否受累。方法采集家系成员外周血标本及受检孕妇羊水标本,常规提取基因组DNA,以DNA测序方法进行基因突变分析,并对基因一侧的微卫星多态标记进行分析。结果 3个家系先证者为双重杂合子,一个家系先证者为纯合子,均分别来自父方和母方,待测胎儿有3例不含这两种突变,1例为杂合子。结论对PTPS基因而言,此4家系的第二胎为完全正常。

Objective To diagnose the atypical phenyl ketonuria （PKU） by DNA mutation analysis for.the second fetuses from 4 families with atypical PKU children born due to 6-pyruvoyl tetrahydropterin synthase （ PTPS ） defects. Methods Peripheral blood of the pedigrees and the amniocytes of the pregnant women were collected and DNA was extracted from lymphocytes and amniocytes. The DNA sequencing was performed to check mutations, and microsatellite marker analysis was performed. Results The 3 probands of the families were double heterozygotes and 1 proband was homozygote, in which the mutations were from their father and mother, respectively. The 3 fetuses were confirmed to have none of the two mutations, and 1 fetus only had one mutation. Conclusion These 4 fetuses had been diagnosed to be normal on his （ or her ） PTPS gene. And a normal phenotype has been confirmed by clinical manifestation, biochemical test and repeated DNA check on the newborn baby.