Abstract
The question of whether Vitamin B12 can prevent fetal accumulation of methylmalonic acid (MMA) in the vitamin-responsive form of the disease was investigated for the first time. During the second pregnancy of a woman who had previously lost a child with presumed MMA-emia, sonicated amniotic fluid cells initially showed no activity of MM-CoA Mutase and no accumulation of the coenzyme 5'-deoxyadenosylcobalamin. Full activity of the enzyme was restored with the addition of this cofactor. Vitamin B12 in large doses was given to the mother from 32 wks. gestation to term. Maternal serum B12 levels reached 3,000-6,000 pg/ml (normal < 900) in the last 6 weeks. Cord blood B12 was over 19,000 pg/ml; maternal serum B12 taken simultaneously measured over 18,000. Instead of the anticipated progressive increase in maternal urinary MMA during the last 2 months of pregnancy, there was a decrease. Following birth, the infant's urinary MMA content was 67/μm/mg creatinine (normal < 5.0), and has remained essentially the same for the first 5 weeks of life on a diet containing 1.5 gm protein/Kg/day; thus far supplemental B12 has not been necessary. Skin biopsy studies to confirm B12 responsiveness are nearing completion. It seems likely that administration of large doses of Vitamin B12 to mothers carrying fetuses with the B12 responsive form of MMA-emia can slow prenatal accumulation of MMA.
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Ampola, M., Mahoney, M., Nakamura, E. et al. IN UTERO TREATMENT OF METHYLMALONIC ACIDEMIA (MMA-EMIA) WITH VITAMIN B12. Pediatr Res 8, 387 (1974). https://doi.org/10.1203/00006450-197404000-00280
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DOI: https://doi.org/10.1203/00006450-197404000-00280