Case-control study of vitamin B12 and metabolite MMA and transporter TCN2 in children with ASD

Objective To investigate the level of vitamin B12 in children with autism spectrum disorder (ASD), and provide a theoretical basis for early detection and drug treatment of ASD. Methods A total of 89 ASD cases and 89 matched controls were collected. The levels of urinary methylmalonic acid (MMA) and serum vitamin B12, Transcobalamin Ⅱ (TCN2) were determined by enzyme-linked immunosorbent assay (ELISA). TCN2 gene rs1801198 was genotyped by SNaPshot. Results The serum levels of vitamin B12 and TCN2 in children with ASD [ (369.08±131.88) pmol/L, (1.56±0.16) ng/mL] were significantly lower than those in the control group[ (485.16±200.33) pmol/L, (1.71±0.17) ng/mL] (t=-5.47,-5.92, P<0.05). The level of MMA in urine of ASD children [ (758.97±106.96) ng/mL] was significantly higher than that in the control group[ (693.66±121.72) ng/mL] (t=3.94, P<0.05); The genetic polymorphism of rs1801198 locus was not associated with the risk of ASD (P>0.05), and there was no significant correlation with serum TCN2 level (F=1.16, P>0.05). Conclusion ASD children are at a potential deficiency of vitamin B12 and should strengthen their nutritional interventions while conducting ASD interventions.