PGM3-congenital disorder of glycosylation

PGM3-congenital disorder of glycosylation (PGM3-CDG) is an inherited condition that primarily affects the immune system but can also involve other areas of the body. The pattern and severity of this disorder's signs and symptoms typically vary.

Most people with PGM3-CDG have impaired immune function (immune deficiency). Many have a shortage of white blood cells (leukopenia), which normally protect the body from infection. Because affected individuals lack the necessary immune cells to fight off certain bacteria, viruses, and fungi, they are prone to repeated and persistent infections that often occur in the lungs, ears, skin, or gastrointestinal tract. In severe cases of PGM3-CDG, impaired bone marrow function may lead to a decrease in the production of all blood cells, resulting in a condition called bone marrow failure. Affected individuals usually also have allergies, asthma, or an inflammatory skin condition called eczema. People with PGM3-CDG may develop autoimmunity, which occurs when the body attacks its own tissues and organs by mistake. Persistent illness may cause affected children to grow more slowly than other individuals.

Additionally, people with PGM3-CDG often have abnormally high levels of immune system proteins called antibodies (also known as immunoglobulins), particularly immunoglobulin E (IgE). Antibodies help protect the body against infection by attaching to specific foreign particles and germs, marking them for destruction. The effect of abnormal levels of antibodies in PGM3-CDG is unclear.

People with PGM3-CDG often have intellectual disability, delayed development, and weak muscle tone (hypotonia). Many affected individuals have skeletal abnormalities involving the ribs or bones in the hands, feet, or spine. Some people with this condition have distinct facial features, such as a flat or sunken appearance of the middle of the face (midface hypoplasia), small chin (micrognathia), full lips, downturned corners of the mouth, and wide nostrils that open to the front rather than downward. PGM3-CDG can also cause problems in the lungs, gastrointestinal tract, and kidneys.

Lifespan varies widely in people with PGM3-CDG; some do not survive past infancy while others live into late adulthood.