Clinical Genomics

The Mayo Clinic Congenital Disorders of Glycosylation (CDG) Clinic sees more patients with CDG than any other practice in the U.S. Mayo Clinic specialists of the rare disorder are world experts and have published more than 150 articles related to the condition. They collaborate closely with other departments, including neurology and pediatric neurology, to ensure you get exactly the care you need.

And they constantly strive to improve care through research. Mayo Clinic was the first institution in the U.S. to launch multicenter clinical studies with the involvement of an international association for people with CDG and currently leads a 13-center research consortium. This means, if needed, you have access to the very latest treatment options available and have an opportunity to help others with CDG.

All cells in the human body construct sugar chains attached to proteins called glycoproteins. The construction process, called glycosylation, is essential for the normal function of proteins and lipids throughout the body. The process has many steps, each initiated by an enzyme. Unfortunately, people with certain genetic makeups can lack any one of these enzymes.

People with congenital disorders of glycosylation lack one of these enzymes and can experience a wide range of symptoms. In fact, defects in the glycosylation process affect all of the body's organs and almost all of its functions, including those in the brain, liver and heart, as well as the gastrointestinal, muscle, hormone, clotting and immune systems. Depending on the specific type of CDG, common signs and symptoms include:

• Developmental delays.
• Imbalance.
• Muscle weakness.
• Nerve damage.
• Vision issues.
• Gastrointestinal problems.
• Poor growth.
• Liver disease.
• Bone disease.
• Heart disease.
• Hormone problems.
• Low blood sugar levels.
• Bleeding.
• Clotting risk.

CDG is a hereditary disorder and presents from early childhood to adulthood.

Care tailored to you

To help people with CDG, Mayo Clinic's Congenital Disorders of Glycosylation (CDG) Clinic care team is staffed by specialists, such as:

• Specialized geneticist — provides diagnostic and follow-up care plans and advises on therapy.
• Metabolic nutritionist — works with you to develop a dietary care plan and provides advice on nutrition.
• Metabolic nurse — helps you with care and provides related nursing advice and support.
• Genetic counselor — provides genetic counseling and helps with family testing.
• Pediatric neurologist — provides special expertise for CDG-related neurologic symptoms and care.
• Research coordinator — helps those who want to join research studies.

Because of the complexity of the condition, specialists coordinate your care with multiple specialties and genetic and metabolic laboratories. Even before you visit, the Mayo Clinic CDG Clinic will collect specific information on your or your child's condition. This information will help maximize the benefits of your visit by guiding specialists to schedule appropriate laboratory tests, consults and imaging studies. At the time of your visit, your doctor will have all the necessary data to make an accurate diagnosis and develop a customized care plan. (Download a PDF of the CDG Clinic's Initial Clinic Preparation List.)

Mayo's CDG Clinic evaluates several disorders:

• N-linked glycosylation disorders.
• CDG Ia (PMM2-CDG), CDG Ib (MPI-CDG), CDG Ic (ALG6-CDG) and similar conditions.
• CDG type I.
• CDG type II.
• PGM1-CDG.
• SLC35A2-CDG.
• SLC39A8-CDG.
• TMEM165-CDG.
• Cutis laxa (ARCL2A, ATP6V0A2-CDG, ATP6AP1-CDG and others).
• GPI anchor disorders (PIGV, PIGT, PIGM and others).
• O-linked glycosylation defects (EXT1-CDG, EXT2-CDG and others).
• Combined glycosylation defects.
• NGLY1.

People seen in our Congenital Disorders of Glycosylation (CDG) Clinic also have the opportunity to participate in translational research and the Frontiers in Congenital Disorders of Glycosylation Consortium.