Yes, familial hypercholesterolemia is hereditary. It stems from gene mutations inherited from one or both parents. If one parent carries the mutation, each child has approximately a 50% chance of inheriting it. The mutation affects how the body processes cholesterol and is present from birth.
Three genes cause most cases: LDLR, APOB, and PCSK9. These control how your liver removes LDL cholesterol from your blood. When they're mutated, your liver can't do its job properly — so cholesterol builds up dangerously high right from birth, not because of anything you ate or did. You only need one mutated copy from either parent to be affected. That's called autosomal dominant inheritance. About 1 in 250 to 500 people worldwide have the heterozygous form, meaning one mutated copy. The homozygous version — where both parents pass along a mutation — is far rarer, affecting roughly 1 in 160,000 to 1 million people. But when it happens, cholesterol levels climb to extreme heights and heart disease can begin in childhood, sometimes before age 10.
Your risk goes up significantly if a parent, sibling, or grandparent has familial hypercholesterolemia. Kids with one affected parent face that 50% chance with every pregnancy. Pay close attention if your family history includes early heart attacks or strokes — before 55 in men, before 65 in women — especially in people who weren't smokers and didn't have obvious weight or lifestyle issues. Someone with very high LDL in their 20s or 30s despite a healthy diet and regular exercise should raise a flag. So should physical signs like xanthomas (fatty lumps under the skin near tendons), or corneal arcus (a pale white ring around the iris of the eye). These aren't just cosmetic quirks — they're cholesterol deposits the body has literally run out of places to store. Some countries have moved toward cascade screening, where diagnosing one family member triggers testing of all first-degree relatives. The Netherlands pioneered this approach nationally and identified thousands of cases that would otherwise have gone undetected for years. Catching it early is the whole game.
Here's what people get wrong: thinking familial hypercholesterolemia only hits people with bad diets or weight problems. That's backwards. Genetics drives this entirely, no matter how clean you eat or how much you exercise. Another mistake? Assuming high cholesterol means you have familial hypercholesterolemia. Most high cholesterol comes straight from lifestyle choices. Genetic testing and family history are what actually separate the genetic cases from the rest. People also panic thinking they'll definitely have a heart attack as a teenager. The homozygous form is serious, sure. But many people with the heterozygous version live decades without problems if they stay on statins, PCSK9 inhibitors, or other medications. This isn't a death sentence when you catch it early and stick with treatment.
Not necessarily. You inherit one gene copy from each parent. You might get a normal copy from one and a mutated copy from the other — that's heterozygous familial hypercholesterolemia. Or you could inherit two mutated copies, which is the homozygous form and considerably more severe. Genetic testing is the only way to know for certain which situation you're in. Either way, knowing gives you and your doctor a real starting point.
Yes, absolutely. Your grandparent passed the mutation to one of your parents, who may have passed it to you. These mutations follow a direct line through families — they don't skip generations in the way some recessive conditions do. Severity can vary between relatives even with the same mutation, which sometimes makes it harder to spot. A genetic counselor can map out exactly how it's moved through your family tree and who else might need testing.
Start with a lipid panel and talk to your doctor about genetic testing, particularly if you're over 20 or have relatives who had heart disease early. A cardiologist or lipidologist — a specialist in cholesterol disorders — can interpret your results and build a treatment plan that typically includes statins, possibly PCSK9 inhibitors, and lifestyle strategies. Don't stop there though. Your siblings and children face the same risk, so loop them in. Getting everyone screened early is one of the most practical things you can do for your whole family.