Abstract Background Methylmalonic acidemia with homocystinuria is caused by a rare inborn error of vitamin B12 (cobalamin) metabolism. There are four complementation classes cobalamin defects cblC, cblD, cblF, and cblJ that responsible for combined methylmalonic homocystinuria. Case presentation We report case Pakistani family composed six children diagnosed (MMA + HCU). Mutation analysis sibli...

In 1970 we wrote: “The first major phase in the clinical investigation of vitamin B,? metabolism and its derangements began with the development and application of methods for the estimation of total Bl2 in tissues and body fluids and the assay of total serum vitamin Bl2 has been a routine diagnostic procedure for many years. Most of the information obtainable by such methods has been gained an...

Methionine synthase reductase (MSR) deficiency is an autosomal recessive disorder of folate/cobalamin metabolism leading to hyperhomocysteinemia, hypo- methioninemia and megaloblastic anemia. Deficiency in MSR activity occurs as the result of a defect in the MSR enzyme, which is required for the reductive activation of methionine synthase (MS). MS itself is responsible for the folate/cobalamin-...

Cobalamin is an essential molecule for humans. It acts as a cofactor in one-carbon transfers through methylation and molecular rearrangement. These functions take place in fatty acid, amino acid and nucleic acid metabolic pathways. The deficiency of vitamin B12 is clinically manifested in the blood and nervous system where the cobalamin plays a key role in cell replication and in fatty acid met...

Glioblastoma is an exceptionally difficult cancer to treat. Cancer is universally marked by epigenetic changes, which play key roles in sustaining a malignant phenotype, in addition to disease progression and patient survival. Studies have shown strong links between the cellular redox state and epigenetics. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a redox-sensitive transcription fa...

Because the origin of cobalamin (vitamin B12) analogues in animal chows and animal and human blood and tissues is unknown, we investigated the possibility that multivitamin interactions might convert cobalamin to cobalamin analogues. We homogenized three popular multivitamin-mineral pills in water, incubated them at 37 degrees C for 2 h, and isolated the cobalamin. Using paper chromatography we...

Chronic exposure to arsenic is occurring throughout South and East Asia due to groundwater contamination of well water. Variability in susceptibility to arsenic toxicity may be related to nutritional status. Arsenic is methylated to monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) via one-carbon metabolism, a biochemical pathway that is dependent on folate. The majority of one-carbon...

There is an increasing evidence that Helicobacter pylori may interfere with gastrointestinal metabolism of micronutrients and drugs such as iron, cobalamin, thyroxine and levodopa, with relevant clinical effects. In this review we examine the strength of the causal association and the plausible pathophysiologic mechanisms underlying these adverse effects.