Is an ultra-rare inherited condition affecting a specific type of glycosylation, called N-linked glycosylation. Symptoms often include generalized hypotonia, developmental delays, less developed genitalia, seizures, feeding difficulties, shallow breathing, distinct facial features, and hypogammaglobulinemia.
Symptoms
People with MOGS-CDG often have low muscle tone (generalized hypotonia), developmental delays, less developed genitalia, seizures, feeding difficulties, and shallow breathing (hypoventilation). They often also have shared facial features, including differences in the shape of the skull (a prominent occiput), long eyelashes, a broad nose, a small chin, short palpebral fissures (length between the inner and outer corner of the eye), and a high arched palate. People with MOGS-CDG have immune abnormality including severe hypogammaglobulinemia (low immunoglobulin or antibody levels in the blood) with swelling and increased resistance to some viral infections (particularly enveloped viruses).
Diagnosis
Other CDGs are often diagnosed based on a blood test that looks at if common proteins in the blood (like a glycoprotein called transferrin) are properly glycosylated or not. This test cannot be used in MOGS-CDG as it is normal in people with MOGS-CDG. A different test called urine oligosaccharides is often able to diagnose MOGS-CDG. To confirm a diagnosis, we do genetic testing in blood. People with MOGS-CDG have two non-working copies of the MOGS gene, most often inheriting one non-working copy from each parent.
Treatment and Prognosis
There is a potential immunologic intervention treatment for MOGS-CDG by giving immunoglobulin to patients via IV or subcutaneous injection. In general, treatment for MOGS-CDG focuses on identifying treatable medical conditions and preventing complications. This may include supportive treatment, physical therapy, occupational therapy, etc.