Overview of Carbohydrate Metabolism Disorders

ByMatt Demczko, MD, Mitochondrial Medicine, Children's Hospital of Philadelphia
Reviewed/Revised Mar 2024
VIEW PROFESSIONAL VERSION

Carbohydrate metabolism disorders are hereditary metabolic disorders. Hereditary disorders occur when parents pass on to their children the defective genes that cause these disorders.

There are different types of inherited disorders. In many hereditary metabolic disorders, both parents of the affected child carry 1 copy of the abnormal gene. Because usually 2 copies of the abnormal (recessive) gene are necessary for the disorder to occur, usually neither parent has the disorder. Some hereditary metabolic disorders are X-linked, which means only 1 copy of the abnormal gene can cause the disorder in boys. (See also Overview of Hereditary Metabolic Disorders.)

Carbohydrates are sugars. Some sugars are simple, and others are more complex. Sucrose (table sugar) is made of 2 simpler sugars called glucose and fructose. Lactose (milk sugar) is made of glucose and galactose. Both sucrose and lactose must be broken down into their component sugars by enzymes before the body can absorb and use them. The carbohydrates in bread, pasta, rice, and other carbohydrate-containing foods are long chains of simple sugar molecules. These longer molecules must also be broken down by the body. If an enzyme that is needed to process a certain sugar is missing, that sugar can accumulate in the body, causing problems.

Disorders of carbohydrate metabolism include

More Information

The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.

  1. 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.

  2. Genetic and Rare Diseases Information Center (GARD): This resource provides and easy to understand information about rare or genetic diseases.

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