Types of Hereditary Cholesterol Disease
There are many types of hereditary cholesterol diseases. Some of the most common ones include:
• Familial hypercholesterolemia (FH)
• Autosomal dominant hypercholesterolemia (ADH)
• Familial combined hyperlipidemia (FCHL)
• Homozygous familial hypercholesterolemia (HoFH)
Each of these diseases is caused by a genetic mutation that affects how the body handles cholesterol. As a result, people who have these conditions tend to have high cholesterol levels in their blood, leading to serious health problems.
Treatments are available for all of these diseases, but they vary depending on the specific condition. For example, HoFH can’t be treated with medication because people who have that condition cannot produce any functional LDL receptors. On the other hand, FH and ADH are often treatable with statins. In
Many people who have these conditions start taking statins as children to control their cholesterol levels.
Familial hypercholesterolemia (FH):
Symptoms:
Familial hypercholesterolemia is a common hereditary disease that causes high levels of LDL cholesterol and triglycerides in the blood. The condition can lead to early heart attack, stroke, and other serious health problems. The symptoms tend to appear during childhood or young adulthood and may include:
• High levels of LDL-C (bad cholesterol)
• Heart or circulatory problems caused by fatty deposits on artery walls
• Stroke or heart attack at a relatively young age
People with FH need to take a statins medication if diagnosed with the disease.
• Statins are a class of drugs that can help control cholesterol levels by blocking an enzyme needed to produce LDL receptors.
• As FH grows older, they are also encouraged to eat a low-fat diet and exercise regularly to keep their heart healthy.
Autosomal dominant hypercholesterolemia (ADH):
Symptoms:
Like FH, ADH causes high LDL cholesterol and triglyceride levels in the blood. It may lead to serious health problems such as:
• Heart or circulatory problems caused by fatty deposits on artery walls
• Atherosclerosis (hardening of the arteries due to plaque buildup)
Treatment:
As with FH, treatment for ADH usually involves taking a medication called statins.
• Statins effectively control cholesterol levels and prevent the progression of atherosclerosis in people who have ADH.
Affected individuals should also adopt a heart-healthy diet and exercise routine to protect their health and prevent future problems.
Familial combined hyperlipidemia (FCHL)
Symptoms:
People who have FCHL tend to have – high LDL-C – high triglycerides – low HDL-C – small dense LDL particles – abdominal obesity – insulin resistance. However, they don’t necessarily experience any symptoms due to these conditions. Those who do may develop:
• Heart or circulatory problems caused by fatty deposits on artery walls
• High blood pressure
• Stroke or heart attack at a relatively young age Treatment:- FCHL is often treated with statins and other types of drugs to control cholesterol levels, improve insulin resistance, and lower the risk of cardiovascular disease.
• Statins reduce LDL-C and increase HDL-C levels in people who have FCHL. Other medications such as fibrates (which help lower triglycerides and raise HDL-C) and bile acid sequestrants (which lower LDL-C) may also be prescribed.
Homozygous familial hypercholesterolemia (HoFH)
Symptoms:
HoFH is a rare inherited disorder that causes extremely high LDL cholesterol levels in the blood from birth. Not everyone who has HoFH experiences symptoms. Those who do may have:
• Heart or circulatory problems caused by fatty deposits on artery walls
• Atherosclerosis (hardening of the arteries due to plaque buildup)
• High blood pressure
Familial hypercholesterolemia:
A disease in which a defective protein causes an abnormal increase in cholesterol (a type of fat) and other lipids (fatty substances) in the blood. This disease causes severe atherosclerosis (“hardening”) of the arteries, leading to heart attacks and strokes at any age. It is usually inherited as an autosomal dominant trait.
Familial hypercholesterolemia (FH), also known as familial hyperlipoproteinemia (PHP), is a genetic disorder characterized by high levels of low-density lipoprotein cholesterol (LDL-C, “bad” cholesterol) and triglycerides, and frequent premature coronary artery disease commonly presenting in young adulthood, despite little or no elevation of serum cholesterol. It is inherited as an autosomal dominant condition, and researchers estimate that FH affects between 1 in 250 and 1 in 500 people worldwide.
The common signs and symptoms include:
Risk factors include:
FH has an autosomal dominant mode of inheritance, but rare cases of recessive inheritance have been reported. Mutations cause most patients to the LDL receptor gene (LDLR), which encodes for a cell surface receptor that binds and internalizes LDL from the bloodstream.
In FH patients with two defective copies of the LDLR gene, there is very little or no functional LDLR protein at all, leading to substantially increased blood levels of LDL along with other negative consequences. LDL is not adequately cleared from the blood in these patients, resulting in elevated cholesterol levels throughout one’s life.
Familial hypercholesterolemia cause:
The underlying cause of FH is the decreased production or function of the LDL receptor protein. This causes an increased LDL level in the blood, leading to abnormally high cholesterol levels that lead to atherosclerosis. Patients with homozygous FH (two defective copies) will begin having lipid issues very young and typically suffer heart attacks by age 20.
For patients with heterozygous FH (one defective copy), early diagnosis typically leads to lifestyle changes that can slow down or stop the advancement of atherosclerosis. However, these individuals are at risk for CAD later in life. Approximately one-third of people diagnosed after age 60 experience cardiovascular disease over ten years earlier than average (i.e., 50’s vs. ‘ the 70s).
Familial hypercholesterolemia types:
There are three types of FH:
Type I, or “classic” FH, is the most common and is caused by mutations to the LDLR gene.
Type II, or “non-classic” FH, is caused by mutations to other genes that encode proteins involved in lipid metabolism. This type is less common than type I.
Type III, or “severe” FH, is a rare disease caused by defects in multiple genes involved in lipid metabolism.
familial hypercholesterolemia treatments:
There is no cure for FH, but there are several treatments available that can help to lower cholesterol levels and reduce the risk of cardiovascular disease:
Lifestyle changes, including dietary modifications, exercise, and weight loss.
Medications such as statins work by blocking cholesterol synthesis in the liver.
LDL apheresis is a procedure in which a machine removes LDL from the blood.
Cholesterol absorption inhibitors block the absorption of cholesterol from food into the bloodstream.
PCSK9 inhibitors, a new class of medications that inhibit the function of PCSK9, a protein that inhibits the LDL receptor.
There is no cure for FH, but most patients can live long and healthy lives with early diagnosis and proper treatment. Cardiovascular disease can be prevented or delayed in these patients by making lifestyle changes and taking medications to lower cholesterol levels. For patients with homozygous FH, LDL apheresis and cholesterol absorption inhibitors are the best options for preventing heart attacks and death.
is familial hypercholesterolemia dominant or recessive:
FH is an autosomal dominant disorder, meaning that a single copy of the defective gene is enough to cause the disease. However, rare cases of recessive inheritance have been reported. Mutations cause most cases of FH to the LDL receptor gene (LDLR), which encodes for a cell surface receptor that binds and internalizes LDL from the bloodstream.
In FH patients with two defective copies of the LDLR gene, there is very little or no functional LDLR protein at all, leading to substantially increased blood levels of LDL along with other negative consequences. LDL is not adequately cleared from the blood in these patients, resulting in elevated cholesterol levels throughout one’s life.
For patients with heterozygous FH (one defective copy), early diagnosis typically leads to lifestyle changes that can slow down or stop the advancement of atherosclerosis. However, these individuals are at risk for CAD later in life. Approximately one-third of people diagnosed after age 60 experience cardiovascular disease over ten years earlier than average (i.e., 50’s vs. ‘ the 70s).
FH is an autosomal dominant disorder, meaning that a single copy of the defective gene is enough to cause the disease. However, rare cases of recessive inheritance have been reported. Mutations cause most cases of FH to the LDL receptor gene (LDLR), which encodes for a cell surface receptor that binds and internalizes LDL from the bloodstream.
In FH patients with two defective copies of the LDLR gene, there is very little or no functional LDLR protein at all, leading to substantially increased blood levels of LDL along with other negative consequences. LDL is not adequately cleared from the blood in these patients, resulting in elevated cholesterol levels throughout one’s life.