Two cases of benign methylmalonic aciduria detected during a pilot study of neonatal urine screening.
Two cases of benign methylmalonic aciduria (MMAuria) were found among 9780 neonatal screenings using the previously described screening method consisting of urease digestion, ethanol deproteinization and gas chromatography-mass spectrometry. Combining this screening method with the stable isotope dilution technique showed very specific and sensitive measurements of methylmalonic acid in urine. The concentrations of urinary methylmalonic acid were measured at several ages. The levels of urinary methylmalonic acid in two patients varied from 0.27 to 3.04 mol/mol creatinine (control<0.01 mol/mol creatinine). Methylcitrate and homocystine were not increased in the patient's urine or blood. Blood propionylcarnitine was also at normal levels. The urinary methylmalonate excretions were decreased to the levels of about 50% of the start point after vitamin B12 treatment in one patient, but the other patient showed no change. No clinical abnormalities were observed during these periods.
Shinka
Toshihiro
T
Division of Human Genetics, Medical Research Institute, Kanazawa Medical, University, 1-1 Daigaku, Uchinada, Ishikawa 920-0293, Japan. shinka@kanazawa-med.ac.jp
Inoue
Yoshito
Y
Yoshino
Makoto
M
Kakinuma
Hiroaki
H
Takahashi
Hiroaki
H
Kuhara
Tomiko
T
D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008661:Metabolism, Inborn Errors / Q000175:diagnosis* / Q000652:urine; D008764:Methylmalonic Acid / Q000652:urine*; D015997:Neonatal Screening; D010865:Pilot Projects; D012015:Reference Standards
D008764:Methylmalonic Acid