Abstract: Objective   To acquire more knowledge about neonatal and prevent and treat it better by investigating the clinical feature and therapeutic experience about it. Methods    7 cases with Neonatal methylmalonic aciduria who were seen in Tianjin Children’s Hospital from Jan 2009 to Oct 2012 are reported in this paper and 12 cases reported previously in recent seven years in China were reviewed. Result   Totally 19 cases were summarized, 11 males and 8 females. Ages of onset were from 24 hours to 27 days. The main clinical manifestations were feeding difficulty, dyspnoea, twitch, et al. Routine laboratory examinations were metabolic acidosis, hyperammoniemia, et al. GC-MS analysis of urinary organic acid declared that 19 cases’ Urinary methylmalonic acid concentration were significantly higher. 10 cases died, 6 cases significant hypoevolutism during 2 to 8 months follow-up visits, 3 cases lost because of giving up treatment. Conclusion   Neonatal methylmalonic aciduria has nonspecific symptoms early such as feeding difficulty, et al. Routine examinations were short of specificity. Fatality rate and disability rate were very higher. In order to diagnose and treat early, we should detect the amino acids of blood and urine of suspected cases in time. So then we can improve the prognosis.

Key words: neonate