Familial hyperlipidemia type 5

Familial hyperlipidemias are classified according to the Fredrickson classification. Type V familial hyperlipidemia is also known as combined hyperlipidemia as it look like a combination of type I and type IV. In type V familial hyperlipidemia there is an increase in both chylomicrons and VLDL. Both of the lipoproteins are hydrolyzed by LPL. However, this is mainly caused by mutations in APOA5. APOA5 plays a role in stablizing the APOC2-LPL complex, which is needed to hydrolize VLDL and chylomicrons. Mutations in APOA5 would therefore lead to instability of this complex and less hydrolysis. Some cases have also shown a decrease in LPL itself, which was mostly linked to the VLDL increase.

家族性高脂血症按照弗雷德里克森分类法进行分类。V型家族性高脂血症亦称为混合型高脂血症，因其表现类似I型和IV型的结合。在V型家族性高脂血症中，乳糜微粒和极低密度脂蛋白（VLDL）的水平均有所上升。这两种脂蛋白均被脂蛋白脂酶（LPL）水解。然而，这一现象主要是由APOA5基因突变引起的。APOA5在稳定APOC2-LPL复合物方面发挥作用，而该复合物对于VLDL和乳糜微粒的水解至关重要。因此，APOA5基因的突变会导致该复合物的不稳定和分解作用减弱。在某些病例中，脂蛋白脂酶（LPL）本身水平也有所下降，这主要与VLDL水平的升高有关。