A congenital disorder of glycosylation (CDG) is a term that applies to a group of genetic diseases that affect glycosylation, which is the chemical process by which sugars are branched into “trees” and form molecules called glycoproteins. These compounds are important for the body to function normally, and a deficiency in them may cause problems in many organs.
There are many symptoms associated with CDGs. Specific symptoms usually range in severity depending upon the type of CDG. Despite the wide variety in symptoms, almost all CDGs have distinct neurologic symptoms such as decreased muscle tone, seizures, developmental disabilities, cognitive disabilities, or problems with coordination. Other common symptoms include feeding problems, abnormal bleeding or blood clotting, unusual fat distribution, vomiting or diarrhea, crossed eyes, abnormal facial features, and low blood sugar. Liver and heart problems have also been reported.
There are many types of CDGs, and each type is caused by a different genetic mutation, but almost all are inherited in an autosomal recessive manner. This means that someone would need two mutated genes to have the condition.
CDGs can be first diagnosed by examining any current symptoms and family medical history. Blood tests may also be conducted to screen for glycoprotein defects. Prenatal diagnosis may also be available if a parent is a known carrier of a CDG-causing genetic mutation. There are not many specific therapies for most forms of CDG – treatment is aimed at making symptoms more manageable and may require many medical specialists like neurologists or speech pathologists working together. Genetic counseling is often recommended for affected individuals and their families.
If you or a family member has been diagnosed with a CDG, speak with your doctor to learn more information. Support groups may also be available for further resources.
Description Last Updated: Aug 21, 2018