Library · Disease
Familial hypercholesterolemia
Make it clearer
Familial hypercholesterolemia is a group of inherited genetic defects that raise blood cholesterol dramatically.
The same circuit always fails, even though the mutation is not the same. One affects the LDL receptor, the part the liver uses to grab LDL cholesterol and pull it out of circulation. Another affects apolipoprotein B, the piece of LDL that the receptor recognizes. And the third affects PCSK9, a protein that regulates how many receptors stay available. The liver clears LDL with receptors; if the receptor does not latch on, LDL keeps circulating. That is the common endpoint of all three.
And LDL that keeps circulating does damage: it raises the risk of atherosclerosis, the hardening and narrowing of the arteries from fatty deposits. Sometimes cholesterol also builds up in the tendons and thickens them; that is called a tendon xanthoma, and it is a pathognomonic sign, meaning that when it shows up it points to this disease and not another.
In brief
Familial hypercholesterolemia is a group of inherited genetic defects that markedly raise the serum cholesterol level.
The three main mutations affect the LDL receptor, apolipoprotein B, or PCSK9, and they all end the same way: the receptor does not bind LDL, and the liver clears less of it.
If the liver's receptor does not latch on, LDL keeps circulating.
That high LDL raises the risk of atherosclerotic disease, and tendon xanthomas are a pathognomonic sign.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingFamilial Hypercholesterolemia, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated