遗传病论文

半乳糖血症的诊断与防治

摘要：目的：应用气相色谱质谱( GC-MS）技术检测10例半乳糖血症患儿治疗前后尿液.以建立半乳糖血症的化学诊断方法。方法：留取10例半乳糖血症患儿治疗前后尿液和60例同年龄段正常儿童尿液.尿液经尿素酶处理后GC-M S检测尿代谢产物。结果半乳糖血症患儿尿中检测出至少34种代谢物.其中半乳糖、半乳糖醇、半乳糖酸、酪氨酸、4-羟基苯乙酸、4-羟基苯乳酸水平均较正常对照组明显升高(P均<0. O5).二氢尿嘧啶水平较正常对照组显著降低(P < 0. O5) ,治疗后除4-羟基苯乳酸外，其他均恢复至正常范围。结论：GC-MS检测尿中半乳糖、半乳糖醇、半乳糖酸水平可诊断半乳糖血症。

关键词：半乳糖血症；气相色谱-质谱；尿素酶

Abstract: Objective To establish chemical diagnosis method of galaetosemia and detect urine metabolites in 10 cases with galae- tosemia by gas chromatography- mass spectrometry. Method Ten cases with galactosemia s urine before and after treatment and 60 nor mal children's urine were analyzed by ureasepretreated gas

chromatography- mass spectrometry method. Results At least 34 met abolites could be detected in galactosemia patients' urine, tyrosine, 4- hydroxybenzene acztic acid, 4- hydroxybenzene lactate, galactose, galaetitol and galactonic acid in pre- treatment galactosemia patients, which were significantly higher than those in normal control group(all P<0. O5).and the level of urine 2, 4- dihydropyrimindine in pre- treated galactosemia patients was significantly lower than that in normal controlgroup(P< 0.05).Those metabolites elevated in pre- treated galactosemia patients urine became normal after treatment exczpt 4- hydroxybenzene lactate. Conclusion Galactosemia may be chemically diagnosed according to urine galactose, galactitol and galactonic acid determination by gas chromatography- mass spectrometry. Key words: galactosemis; gas chromatography-mass spectrometry; Urease

半乳糖血症是半乳糖代谢中酶的功能缺陷所引起的一种常染色体隐性遗传代谢性疾病。半乳糖代谢中半乳糖激酶、半乳糖-1-磷酸尿苷酰转移酶和尿苷二磷酸-半乳糖-4-异构酶缺陷均可引起半乳糖血症。通常所说的经典半乳糖血症是半乳糖基转移酶缺乏引起的半乳糖血症，其发病率为0. 1/ 4000~0. 0 1 / 4000 。 半乳糖血症是由于半乳糖代谢途径中酶的缺陷所引起的一种常染色体隐性遗传代谢性疾病。乳糖是体内半乳糖的主要来源，正常情况下，乳糖进入肠道后即被水解成半乳糖和葡萄糖经肠茹膜吸收入血循环，然后半乳糖在肝脏先后经半乳糖激酶( GALK)、半乳糖-1-磷酸尿普酞转移酶(GALT)以及尿普二磷酸一半乳 糖一4一差向异构酶(GALE)的催化作用，最终生成1-磷酸葡萄糖进入葡萄糖代谢途径。半乳糖代谢过程中任何一种酶缺乏均可引起半乳糖和(或)半乳糖一1一磷酸及其旁路代谢产物(如半乳糖醇等)增加，这些异常代谢产物会在肝、肾、脑、晶状体等各种组织堆积，引起相应脏器功能损害。另外，半乳糖一1-磷酸对糖代谢途径中的多种酶有抑制作用，可阻断糖原分解过程;高浓度的半乳糖一1-磷酸还抑制葡萄糖异生过程.导致低血糖。

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