Homologous G776G Variant of Gene is Linked to Vitamin B12 Deficiency.

Vitamin B12 (Cobalamin) deficiency, due to improper internalization of cobalamin, is a metabolic disorder prevalent in impoverished and elderly populations and is associated with megaloblastic anemia and dementia. It has been suggested that mutations in transcobalamin II () or gastric intrinsic factor (GIF) proteins can alter their binding efficiency to cobalamin or reduce the ability of their receptors to internalize them. In this case-control study, the correlation between vitamin B12 deficiency and alternative alleles of and was investigated in a Jordanian population. One hundred individuals with vitamin B12 deficiency (B12 < 200 mg/mL) were enrolled in our study to evaluate the and polymorphisms. The control group (B12 > 200 mg/mL) included 100 individuals. Our results indicated a significant association between the homologous variant of the gene (G776G) and vitamin B12 deficiency, and an intermediate phenotype in heterozygous individuals ( < 0.001, OR = 5.6, 95% CI = 2.95 to 10.63). The gene, however, showed no correlation between the A68G variant and vitamin B12 deficiency ( = 0.2). This study expounds the association of polymorphism with cobalamin levels in a Jordanian population and highlights the necessity of further studies to elucidate the molecular basis and impact of and genes polymorphisms on vitamin B12 deficiency and associated disorders.