Anemia, memory loss, psychosis and more

Vitamin B12

Vitamin B12 is involved in DNA synthesis and regulation, energy production and red blood cells production. Vitamin B12  deficiency is clinically associated with anemia, neurological disorders like mania, psychosis, and cognitive impairment such as memory loss. Low B12 levels elevates methylmalonic acid and homocysteine.

Most cases of vitamin B12 deficiency are due to poor absorption. Heritable genetic variations are accounted for at least a third of all B12 malabsorption cases.

Vitamin B12 plays key roles in several biological processes, such as DNA synthesis and regulation, energy production and erythropoiesis (red blood cells production).

Vitamin B12 deficiency is clinically associated with megaloblastic anemia, neurological disorders like mania, psychosis, and cognitive impairment such as memory loss. Deficiency in B12 elevates methylmalonic acid and homocysteine.

High homocystaine levels result in irritation, migraines, neurological disorders, anemia, risk for cardiovascular disease and more.

Most cases of vitamin B12 deficiency are due to poor absorption. Heritable genetic variations are accounted for at least a third of all B12 malabsorption cases. Here are the genes involved in genetic susceptibility to vitamin B12 deficiency:

Gene: TRANSCOBALAMIN I (TCN1)

Genomic coordinates (GRCh38): 11:59,852,807-59,866,567


TCN1 is a vitamin B12 binding protein that promotes the cellular uptake of vitamin B12. The TCN1 G variant may reduce transport of cobalamin, resulting in lower plasma vitamin B12 levels.

Gene: TRANSCOBALAMIN II (TCN2)
Genomic coordinates (GRCh38): 22:30,607,082-30,627,059

The TCN2 gene encodes transcobalamin II (TC II), a plasma globulin that acts as the primary transport protein for vitamin B12. Variant form is less efficient in delivering B12 to tissues, and may thus influence susceptibility to B12 deficiency.
 

Gene: CUBILIN (CUBN)
Genomic coordinates (GRCh38): 10:16,823,965-17,130,491

CUBN produces a cobalamin receptor. A missense mutation in exon 8 is predicted to decrease CUBN functionality, thereby lowering vitamin B-12 absorption.