PRENATAL-DIAGNOSIS AND THERAPY FOR A PATIENT WITH VITAMIN-B-12-RESPONSIVE METHYLMALONIC ACIDEMIA

The prenatal therapy is described of a patient with vitamin B-12- resp onsive methylmalonic acidaemia during the last 10 days of gestation wi th oral administration of vitamin B-12 (20mg/day) given to a mother di d not normalize her urinary excretion of methylmalonic acid (MMA), whi ch was 14.5 mmol/mol creatinine at 32 weeks of gestation. Before deliv ery, the mother was excreting 18.9 +/- 3.3 mmol MMA/mol creatinine (me an value at 7 days after vitamin B-12 therapy), as well as at 32 - 37 weeks of gestation with no therapy. After birth, the level of MMA in t he infant's urine was remarkably elevated (500 - 700 mmol/mol creatini ne); the level of MMA in maternal urine decreased dramatically after d elivery. Compared with two previous reports, the length of administrat ion was not sufficient to reduce maternal MMA excretion. In future, th e length of the therapy, route of administration and total dose of vit amin B-12 to maintain an efficient level of vitamin B-12 in an affecte d fetus should be considered.