Question: Is cholesterol genetic? Can a person inherit high cholesterol from his parents if they have high levels? What is FH, and can it be inherited? What are the visible clues for FH? Which test provides accurate information and confirms if one has FH?
Is Cholesterol Hereditary
It is possible for an individual to inherit high blood cholesterol from his parents. Inherited lipid abnormality, excess body weight and other factors can contribute to high cholesterol. When children whose parent or grandparent had premature heart disease were screened, about one-third of the children exhibited some form of lipid abnormality.
Familial Hypercholesterolemia (FH) Causes
Familial hypercholesterolemia (FH) is the most common form of inherited high-cholesterol passed by the genes. This is caused by defective LDL receptors that cannot remove adequate cholesterol from the cells, so there is an accumulation and deposition in the arteries.
FH affects about one individual among five hundred people. If either of the parents of an individual has FH then there is a fifty percent chance of the individual developing heart disease by the age of fifty in a female or by the age of forty if a male. And if an individual has inherited FH from both the parents (this is a very rare case and occurs among one in a million) then he will develop heart disease before the age of twenty and will have very few LDL receptors functioning.
Familial Hypercholesterolemia Symptoms
The clues that hint of FH are –
- If either of the parent or grandparent had a heart attack before the age of sixty (is the biggest clue).
- If ones total cholesterol is above 300-400mg/dL or LDL is higher than 200mg/dL then it is a second clue.
- And if an individual has inherited the FH gene from both the parents then his total cholesterol levels will be between 600 – 1,000mg/dL.
- People with FH may have yellowish raised bumps called xanthomas. They are fatty deposits of cholesterol associated with inherited cholesterol disorder which settle in the elbows, knuckles or tendons of the knees. Xanthomas can also appear in young children, but it usually appears in a person in his twenties or thirties.
- They may also have an opaque ring around the periphery of the cornea of their eyes.
One will be referred to a lipid specialist to perform a test for FH. The test involves extracting cells from skin tissue and growing them in a culture. The positive test for FH confirms that LDL receptors are defective. Tests also may become available which help to identify genetic blood markers called apolipoproteins (any of the protein constituents of lipoprotein) which seem to interfere and affect the clearance of cholesterol in people with inherited disorders.