Familial hyperlipidemia type 4

Familial hyperlipidemias are classified according to the Fredrickson classification. Type IV familial hyperlipidemia is also known as familial hypertriglyceridemia. Typ IV is mostly linked to in increased VLDL within the blood. This is from both an increased production as well as a decreased elimination of VLDL. The increased production is caused by mutations of GCKR. This gene inhibits glucokinase, which would lead to less triglycerides produced in the liver. These triglycerides would then increase the amount of VLDL in the blood. Mutations in GCKR would therefore lead to increased VLDL. A decreased elimination is caused by APOA5. APOA5 plays a role in the hydrolysis of VDLD by LPL. Mutations in this gene would therefore lead to a decrease of this hydrolysis.

家族性高脂血症根据弗雷德里克森分类法进行划分。Ⅳ型家族性高脂血症亦称家族性高甘油三酯血症。Ⅳ型高脂血症主要与血液中极低密度脂蛋白（VLDL）的增加有关，这种增加既源于VLDL的产生增加，也源于其消除减少。VLDL的产生增加由GCKR基因突变引起，该基因抑制葡萄糖激酶，从而导致肝脏产生的甘油三酯减少。这些甘油三酯随后会增加血液中VLDL的含量。因此，GCKR基因的突变会导致VLDL的增加。VLDL的消除减少则由APOA5基因引起，APOA5在LPL的参与下催化VLDL的水解。因此，该基因的突变会导致这种水解作用的减少。