Juvenile megaloblastic anaemia 1
Juvenile megaloblastic anaemia 1 (Imerslund-Grasbeck syndrome) is a disease caused by selective cobalamin malabsorption and inconstant proteinuria. It is caused by mutations in the cubilin (CUBN) or amnionless (AMN) genes.[1]
Pathophysiology
The protein cubilin binds to intrinsic factor-cobalamin complex and is expressed in the distal small intestine and proximal renal tubule. Amnionless is a transmembrane protein that binds tightly to the N-terminal end of cubilin. Together these proteins form the multiligand cubam complex. Mutations in these genes may cause a decrease in the uptake of vitamin B12 leading to megaloblastic anaemia.
References
- ^ Namour F, Dobrovoljski G, Chery C, Audonnet S, Feillet F, Sperl W, Gueant JL (2011) Luminal expression of cubilin is impaired in Imerslund-Grasbeck syndrome with compound AMN mutations in intron 3 and exon 7. Haematologica