Role of (Glu → Arg, Q5R) mutation of the intrinsic factor in pernicious anemia and other causes of low vitamin B12
Pernicious anemia is a vitamin B12 deficiency caused by a lack of gastric intrinsic factor due to an autoimmune chronic atrophic gastritis. Pernicious anemia is typically an adult disease unlike congenital intrinsic factor deficiency, which is also known as juvenile or congenital pernicious anemia (online Mendelian inheritance in man (OMIM) accession no. 261000) .
The intrinsic factor gene was identified and characterized more than a decade ago [2, 3]. As a consequence, a number of abnormalities in the intrinsic factor gene were found in patients with congenital intrinsic factor deficiency [4, 5, 6]. Moreover, a prevalent polymorphism in the intrinsic factor gene was observed, in which glutamic acid was replaced by an arginin in position 5 (Glu → Arg, Q5R) [4, 6]. Apparently, this mutation does not affect intrinsic factor secretion in vitro . However, a possible role of this mutation in ileal vitamin B12 absorption has not been evaluated. Some patients with...
KeywordsIntrinsic Factor Atrophic Gastritis Pernicious Anemia Population Frequency Chronic Atrophic Gastritis
- 4.Gordon MM, Brada N, Remacha A, Badell I, del Rio E, Baiget M, Santer R, Quadros EV, Rothenberg SP, Alpers DH (2004) A genetic polymorphism in the coding region of the gastric intrinsic factor gene (GIF) is associated with congenital intrinsic factor deficiency. Hum Mutat 23:85–91PubMedCrossRefGoogle Scholar