GWAS of serum vitamin B12 and methylmalonic acid (MMA)

Vitamin B12 deficiency can be a serious condition with haematologic and neurologic consequences. Diagnosis of this condition has been hampered by the variability of serum vitB12 measurements. In addition, there have been a few number of SNP’s identified which may modulate serum B12 measurements, like the FUT2 gene. Large scale analysis of serum vitB12 levels with good correction for confounding factors have been lacking. 
Serum MMA may be elevated as a consequence of vitB12 deficiency. MMA may be elevated in the context of reduce3d renal function, and reduced in the context of recent (up to 12 months) use of antibiotics. Again, there have been a few reports on genetic factors influencing serum MMA levels.