Transferrin Isoforms serum

an abnormal pattern of serum transferrin isoforms is found in congenital disorders of glycosylation (also called carbohydrate-deficient glycoprotein or CDG disorders)

CDG disorders result from enzyme defects in the post-translational glycosylation of proteins and are associated with developmental delay, dysmorphic features, mental retardation, neurological deficits, and enteropathy.

specific enzyme tests are required if the transferrin isoform pattern is suggestive of an abnormal pattern.

other conditions such as acute crisis of hereditary fructose intolerance, galactosemia, and acute liver disease may have a congenital disorders of glycosylation (CDG) profile that is indistinguishable from any other true CDG type I cases^[1]

Transferrin glycosylation patterns may normalize so repeat testing is warranted in patients with significant clinical suspicion^[1].

Carbohydrate Deficient Transferrin for Congenital Disorders of Glycosylation, Serum (Mayo Clinic labs)