WP5112 - Familial hyperlipidemia type 5 - Homo sapiens

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.