About Familial Hypercholesterolemia
The New York Center for Rare Diseases supports the mission and guidelines of the Genetic and Rare Diseases Information Center (GARD). The following information is provided by the NIH.
Summary
Hypercholesterolemia due to cholesterol 7alpha-hydroxylase deficiency is a rare, genetic, sterol metabolism disorder characterized by increased LDL cholesterol serum levels (which are resistant to treatment with 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors), hypertrigliceridemia, and decreased rate of bile acid excretion, resulting from cholesterol 7alpha-hydroxylase deficiency. Premature gallstone disease and/or premature coronary and peripheral vascular disease are frequently associated.
Causes
What Causes This Disease?
Genetic Mutations: Hypercholesterolemia due to cholesterol 7alpha-hydroxylase deficiency is caused by genetic mutations, also known as pathogenic variants. Genetic mutations can be hereditary, when parents pass them down to their children, or they may occur randomly when cells are dividing. Genetic mutations may also result from contracted viruses, environmental factors, such as UV radiation from sunlight exposure, or a combination of any of these.
If you suspect you may have this disease, you may want to start collecting your family health history. Information such as other family members who have had similar symptoms, when their/your symptoms first appeared, or exposures to any potential disease-causing environmental factors should be discussed with your medical team.
Known Genetic Mutations: Hypercholesterolemia due to cholesterol 7alpha-hydroxylase deficiency is caused by genetic mutations in the following known gene(s):
CYP7A1
Given these known genetic mutation(s), you may want to ask your health care team if genetic testing is right for you. Genetic tests are laboratory tests that use samples of blood, saliva, or other tissues to help identify changes in genes, chromosomes, or proteins. Genetic testing can help confirm or rule out a suspected genetic disease, or can provide other useful information to your health care team.
Disruption in Metabolism: Hypercholesterolemia due to cholesterol 7alpha-hydroxylase deficiency is caused by a disruption in a person’s metabolism. Metabolism is the series of chemical reactions in our body that turns the food we eat into energy and removes toxins. Hormones and specific proteins, called enzymes, help make the right chemical reactions happen in the right order. However, genetic changes can prevent hormones or enzymes from working properly, which can lead to a disruption in metabolism such as energy not being created for the body or toxins not being removed from the body.