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脂蛋白脂肪酶缺乏症是一种罕见的常染色体隐性遗传病。其生化特点是血浆脂蛋白脂肪酶(LPL)活性显著降低或完全缺失,空腹血中乳糜微粒和甘油三脂水平明显升高。LPL是一种由两个相同亚基构成的糖蛋白,基因定位于8号染色体的短臂上(8p22)。LPL基因由10个外显子组成,分布范围约30kb。引起LPL缺乏症的基因变异有两种类型,一是基因中DNA片段的丢失或插入等造成的结构重排,二是LPL基因的点突变。目前发现的突变有6～7种,多数不影响LPL基因的表达,但分别导致成熟LPL中不同氨基酸的置换。这些氨基酸都处于LPL分子的功能区,它们的置换可破坏LPL的活性和影响酶的其他性质。
Lipoprotein lipase deficiency is a rare autosomal recessive disease. Its biochemical feature is a significant reduction or complete loss of plasma lipoprotein lipase (LPL) activity, a significant increase in the level of chylomicrons and triglycerides in fasting blood. LPL is a glycoprotein composed of two identical subunits. The gene is located on the short arm of chromosome 8 (8p22). LPL gene consists of 10 exons, the distribution of about 30kb. There are two types of genetic variation that cause LPL deficiency. One is structural rearrangement caused by the loss or insertion of a DNA fragment in the gene, and the second is point mutation in the LPL gene. Currently, there are 6 to 7 mutations found, most of which do not affect the expression of LPL gene, but result in the replacement of different amino acids in mature LPL respectively. These amino acids are located in the LPL molecule’s functional area, their replacement can destroy the activity of LPL and affect other properties of the enzyme.