Lipid metabolism disorders are hereditary metabolic disorders Overview of Hereditary Metabolic Disorders Hereditary metabolic disorders are inherited genetic conditions that cause metabolism problems. Heredity is the passing of genes from one generation to the next. Children inherit their parents'... read more . Hereditary disorders occur when parents pass the defective genes Genes Genes are segments of deoxyribonucleic acid (DNA) that contain the code for a specific protein that functions in one or more types of cells in the body or the code for functional ribonucleic... read more 
that cause these disorders on to their children. There are different types of inherited disorders Inheritance of Single-Gene Disorders Genes are segments of deoxyribonucleic acid (DNA) that contain the code for a specific protein that functions in one or more types of cells in the body or code for functional RNA molecules.... read more . In many hereditary metabolic disorders, both parents of the affected child carry a copy of the abnormal gene. Because usually two copies of the abnormal gene are necessary for the disorder to occur, usually neither parent has the disorder.
Lipids are fats Fats Carbohydrates, proteins, and fats are the main types of macronutrients in food (nutrients that are required daily in large quantities). They supply 90% of the dry weight of the diet and 100%... read more , which are an important source of energy for the body. The body’s store of fat is constantly broken down and reassembled to balance the body’s energy needs with the food available. Groups of specific enzymes help the body break down (metabolize) and process fats. Certain abnormalities in these enzymes can lead to the buildup of specific fatty substances that normally would have been broken down by the enzymes. Over time, accumulations of these substances can be harmful to many organs of the body. Lipidoses are disorders caused by the accumulation of lipids.
The accumulation of fatty substances can cause disorders such as
Other enzyme abnormalities prevent the body from converting fats into energy normally. These abnormalities are called fatty acid oxidation disorders Fatty Acid Oxidation Disorders Fatty acid oxidation disorders are lipid metabolism disorders that are caused by a lack or deficiency of the enzymes needed to break down fats, resulting in delayed mental and physical development... read more .
Many lysosomal storage disorders Overview of Lysosomal Storage Disorders Lysosomal storage disorders are hereditary metabolic disorders. Hereditary disorders occur when parents pass the defective genes that cause these disorders on to their children. There are different... read more also involve problems with lipid metabolism.
Before birth, doctors diagnose some lipid metabolism disorders by doing the prenatal screening tests amniocentesis Amniocentesis Prenatal diagnostic testing involves testing the fetus before birth (prenatally) to determine whether the fetus has certain abnormalities, including certain hereditary or spontaneous genetic... read more or chorionic villus sampling Chorionic Villus Sampling Prenatal diagnostic testing involves testing the fetus before birth (prenatally) to determine whether the fetus has certain abnormalities, including certain hereditary or spontaneous genetic... read more . After birth, some lipid metabolism disorders are diagnosed by routine newborn screening tests Newborn Screening Tests Screening tests are done to detect health conditions that are not yet causing symptoms. Many serious disorders that are not apparent at birth can be detected by various screening tests. Early... read more or other tests.
Treatment of lipid metabolism disorders varies depending on the type of fatty substances that accumulate in the blood and tissues.
Cerebrotendinous xanthomatosis
This disorder occurs when cholestanol, a product of cholesterol metabolism, accumulates in tissues. This disease eventually leads to uncoordinated movements, dementia Dementia Dementia is a slow, progressive decline in mental function including memory, thinking, judgment, and the ability to learn. Typically, symptoms include memory loss, problems using language and... read more , cataracts Cataract A cataract is a clouding (opacity) of the lens of the eye that causes a progressive, painless loss of vision. Vision may be blurred, contrast may be lost, and halos may be visible around lights... read more 
, early coronary artery disease Coronary Artery Disease , and fatty growths (xanthomas) on tendons. The disabling symptoms often appear after age 30.
If started early, the drug chenodiol (chenodeoxycholic acid) helps prevent progression of the disease, but it cannot undo any damage already done. People may also given statins because these drugs lower lipid levels in the blood.
Sitosterolemia
In this disorder, fats from fruits and vegetables accumulate in blood and tissues. The buildup of fats leads to atherosclerosis Atherosclerosis Atherosclerosis is a condition in which patchy deposits of fatty material (atheromas or atherosclerotic plaques) develop in the walls of medium-sized and large arteries, leading to reduced or... read more 
, early coronary artery disease Coronary Artery Disease , abnormal red blood cells, and xanthomas on tendons.
Treatment of sitosterolemia consists of reducing the intake of foods that are rich in plant fats, such as vegetable oils, and taking cholestyramine resin. Doctors may also give the drug ezetimibe, which reduces the amount of cholesterol absorbed by the body.
More Information
The following are some English-language resources that may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
National Organization for Rare Disorders (NORD): This resource provides information to parents and families about rare diseases, including a list of rare diseases, support groups, and clinical trial resources.
Genetic and Rare Diseases Information Center (GARD): This resource provides and easy to understand information about rare or genetic diseases.
Drugs Mentioned In This Article
| Generic Name | Select Brand Names |
|---|---|
chenodiol |
Chenodal |
cholestyramine |
Locholest , Locholest Light, Prevalite , Questran, Questran Light |
ezetimibe |
Zetia |
