Lin Bingchun, Huang Yichu, Yu Yanliang, Xiong Xiaoyun, Yang Chuanzhong
Department of Neonatology, Affiliated Shenzhen Maternity & Child Healthcare Hospital, Southern Medical University, Shenzhen, Guangdong Province, China.
Medicine (Baltimore). 2025 Jul 25;104(30):e42046. doi: 10.1097/MD.0000000000042046.
Methylmalonic acidemia (MMA) is a rare disease that is often misdiagnosed and overlooked. Metabolic acidosis and severe hyperammonemia are severe morbidities of MMA that demand immediate treatment.
Here, we describe an MMA neonate with severe hyperammonemia and acidosis that was successfully rescued by continuous renal replacement therapy. A 6-day-old male neonate, with a gestational age of 39 + 3 weeks and a birth weight of 2880 g, was admitted to the emergency with the symptoms of "cyanosis of the face and coma for 2 hours." The infant was suffering from hypoglycemia, hypocalcemia, severe hyperammonemia, and severe metabolic acidosis. After admission, the blood ammonia continued to rise, and continuous renal replacement therapy was promptly administered until the patient gradually regained consciousness. Blood tandem mass spectrometry and profiles revealed that methylmalonic acid and methyl citrate levels were significantly enhanced. Two heterozygous mutations were detected in the MUT gene, confirming the diagnosis of methylmalonic acidemia mut.
The patient's symptoms gradually improved after receiving vitamin B12, l-carnitine, and specialized milk feeding. The patient was successfully discharged from the hospital after 41 days.
甲基丙二酸血症（MMA）是一种罕见疾病，常被误诊和忽视。代谢性酸中毒和严重高氨血症是MMA的严重并发症，需要立即治疗。
在此，我们描述了一名患有严重高氨血症和酸中毒的MMA新生儿，通过持续肾脏替代疗法成功获救。一名6日龄男婴，胎龄39 + 3周，出生体重2880 g，因“面色青紫、昏迷2小时”症状入院急诊。该婴儿患有低血糖、低钙血症、严重高氨血症和严重代谢性酸中毒。入院后血氨持续升高，立即给予持续肾脏替代疗法，直至患者逐渐苏醒。血液串联质谱和谱图显示甲基丙二酸和甲基枸橼酸水平显著升高。在MUT基因中检测到两个杂合突变，确诊为甲基丙二酸血症mut型。
患者在接受维生素B12、左旋肉碱和特殊奶粉喂养后症状逐渐改善。患者在41天后成功出院。
