Intrinsic factor congenital deficiency

Congenital deficiency of IF (so called Immerlund-Syndrome) is the cause of neonatal Pernicious anaemia (Biermer’s Disease). This very rare disease is the consequence of severe cobalamin (vitamin B12) deficiency caused by malabsorption due to the lack of a protein (intrinsic factor, IF) produced by oxyntic glands in the stomach lining. The adult form of IF deficiency or classical pernicious anaemia is more common and appears when the glands of the stomach are destroyed in the course of an autoimmune disease known as atrophic gastritis The increased size of red blood cells (macrocytosis) is corrected by intramuscular injection of cobalamine. Without treatment, complications can occur, including peripheral neuropathy and other injuries.

Synonym: Pernicious anaemia juvenile