Overview of Lysosomal Storage Disorders

Lysosomal storage 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. Some hereditary metabolic disorders are X-linked X-Linked Recessive Disorders , which means only one copy of the abnormal gene can cause the disorder in boys.

Lysosomes are tiny components within cells. Lysosomes contain enzymes that break down (metabolize) many types of molecules entering a cell. When the enzymes do not work correctly, the molecules build up, causing damage in many areas in the body.

Types of lysosomal storage disorders include

Mucopolysaccharidoses occur when the body lacks enzymes needed to break down and store complex sugar molecules (glycosaminoglycans).

Sphingolipidoses occur when people do not have the enzymes needed to break down sphingolipids, which are compounds that protect the cell surface and serve certain functions in the cells. There are many types of sphingolipidoses. The most common sphingolipidosis is

Others sphingolipidoses include

Lipidoses occur when the body lacks one of the enzymes that help the body break down and process 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 (lipids). This 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 include

Before birth, doctors diagnose some lysosomal storage 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 lysosomal storage 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 lysosomal storage disorders varies depending on the substances that accumulate in the blood and tissues.