How does imerslund Grasbeck syndrome lead to vitamin B12 deficiency?
Mutations in the AMN gene prevent cubilin from attaching to the cells in the small intestine and kidneys. Without cubilin function in the small intestine, vitamin B12 is not taken into the body. A shortage of this essential vitamin impairs the proper development of red blood cells, leading to megaloblastic anemia.
What causes intrinsic factor deficiency?
Intrinsic factor deficiency is caused by changes ( mutations ) in the GIF gene and is inherited in an autosomal recessive manner. Treatment generally consists of vitamin B12 injections.
What is congenital pernicious anemia?
JUVENILE “congenital” pernicious anemia is characterized by vitamin B12 deficiency appearing in early life as the result of a congenital lack of gastric intrinsic factor with no other apparent abnormality of the stomach or its secretions.
What is Transcobalamin II deficiency?
Transcobalamin II deficiency is a rare autosomal recessive disorder causing intracellular cobalamin depletion, which in turn causes megaloblastic bone marrow failure, accumulation of homocysteine and methylmalonic acid with clinical findings of failure to thrive, diarrhea, vomiting, pancytopenia, megaloblastic anemia.
Why are the red cells larger than normal in megaloblastic anemia?
Megaloblastic anemia (MA) encompasses a heterogeneous group of anemias characterized by the presence of large red blood cell precursors called megaloblasts in the bone marrow. This condition is due to impaired DNA synthesis, which inhibits nuclear division.
How do you lose intrinsic factor?
Intrinsic factor is a protein made in the stomach….The inability to make intrinsic factor may be caused by several things, such as:
- Chronic gastritis.
- Surgery to remove all or part of the stomach (gastrectomy)
- An autoimmune condition, where the body attacks its own tissues.
How do you know if you have intrinsic factor?
Intrinsic factor antibodies are proteins produced by the immune system that are associated with pernicious anemia. This test detects intrinsic factor antibody (IF antibody) circulating in blood. Intrinsic factor is a protein produced by a type of specialized cells that line the stomach wall known as parietal cells.
Can you take vitamin B12 with polycythemia?
Don’t attempt vitamin B12 therapy without close supervision by your healthcare provider. High numbers of red blood cells (polycythemia vera): The treatment of vitamin B12 deficiency can unmask the symptoms of polycythemia vera.
What causes transcobalamin deficiency?
Mutations in the TCN2 gene cause transcobalamin deficiency. The TCN2 gene provides instructions for making a protein called transcobalamin. This protein attaches (binds) to cobalamin and transports the vitamin to cells throughout the body.