Inherited Cholesterol Disorders--Familial Hypercholesterolemia

What is FH?
Familial Hypercholesterolemia (FH) is an inherited disorder that causes very high cholesterol levels and greatly increases the chance of having a heart attack early in life.  Heart attacks usually occur in men when they are 40-55 years old and in women when they are 50-65 years old.  Unfortunately, they can sometimes occur when people are in their mid-twenties.  The first case of FH was described over 100 years ago and the characteristics of FH passing from generation to generation was understood in the late 1930's.  Actual genetic proof was discovered in the 1960's and 1970's.

What Causes FH?
Cholesterol is removed from the blood by the liver using Low Density Lipoprotein (LDL) receptors. Each person has two genes that are responsible for making the LDL receptors: one received from the father and one received from the mother.  In a person with FH, an abnormal gene was passed on from one parent who has FH and a normal gene was passed on from the other parent. Therefore, half of the LDL receptors are absent or do not work properly and the other half are normal. Because half of the receptors do not remove the cholesterol normally, cholesterol levels increase in the blood. This  results in damage to blood vessels, blockage of arteries and heart attacks at an early age.

How is FH Inherited?
If a person has FH, then each of his or her children will have a 50% chance of inheriting FH.  You are either born with FH or not.  Cholesterol levels can be checked at birth, but the National Cholesterol Education Program (NCEP) guidelines suggest children in a FH family be checked at age two. Most persons with the disease are neither recognized nor treated.

Will I pass on the FH gene if I don't have FH?
If a person has normal cholesterol levels at birth, he or she will never develop FH later in life nor will he or she pass the gene on to their children.

How is FH treated?
FH is treated using diet, medication and, in some cases, LDL-apheresis.  The medication class of choice is the statin medications and include Mevacor ®, Zocor®, Lipitor®, Pravachol® and Lescol®.