Juvenile megaloblastic anaemia 1 (OMIM # 261100) is a rare autosomic disorder characterized by selective cobalamin mal-absorption and inconstant proteinuria produced by mutations in either CUBN or AMN genes.
Megaloblastic anaemia 1 (MGA1) is a rare autosomal recessive condition characterized by selective intestinal vitamin B12 malabsorption and proteinuria.
Several syndromes present with megaloblastic anemia such as congenital megaloblastic anemia due to intrinsic factor defect and juvenile megaloblastic anemia with proteinuria due to defects in the cubilin or the amnionless protein.
Genetically heterogeneous selective intestinal malabsorption of vitamin B12: founder effects, consanguinity, and high clinical awareness explain aggregations in Scandinavia and the Middle East.
Furthermore, the recent characterization of the CUBN gene encoding the intrinsic factor-vitamin B12 receptor (cubilin) provides a basis to identify the causative mutations in patients suffering from a hereditary syndrome of hyperhomocysteinemia that presents with megaloblastic anemia and proteinuria.
Megaloblastic anaemia 1 (MGA1, OMIM 261100) is a rare, autosomal recessive disorder characterized by juvenile megaloblastic anaemia, as well as neurological symptoms that may be the only manifestations.
In conclusion, the present molecular and genetic information on human cubilin now provides circumstantial evidence that an impaired synthesis, processing, or ligand binding of cubilin is the molecular background of this hereditary form of megaloblastic anemia.