megaloblastic anaemia type 1A hereditary form (OMIM:261100) of congenital megaloblastic anaemia due to vitamin B12 deficiency, caused by a defect in the vitamin B12/intrinsic factor receptor.
Caused by defects of:
• AMN, which encodes a protein required for the efficient absorption of vitamin B12; and
• CUBN, which encodes cubilin, a protein that acts as a receptor for intrinsic factor-vitamin B12 complexes.
[Olga Imerslund, Norwegian pediatrician, 1907–1987]
A rare, autosomal recessive form of vitamin B12 deficiency, also known as juvenile-type pernicious anemia.