Abstract
Propionic acidemia (PA) is an autosomal recessively inherited disorder of the organic acid metabolism. It is caused by a deficiency of propionyl-CoA carboxylase (PCC). PCC is a heteropolymeric enzyme composed of ${\alpha}$- and ${\beta}$-subunits. The clinical symptoms of PA are heterogeneous and present vomiting, dehydration, hypotonia, and lethargy, and it can result in death. The typical presentations of neonatal onset PA are life-threatening metabolic acidosis and hyperammonemia. Here, we described a case of neonatal onset PA with mild clinical presentations. She was born to a healthy mother without complications. No significant illness was observed until nine days after birth. She started exhibiting poor oral feeding, vomiting, lethargy, and hypotonia at ten days old. Her laboratory results showed mild hyperammonemia and acidosis. The initial diagnosis was neonatal sepsis and she was treated with antibiotics. However, her clinical symptoms didn't improve. So we considered a metabolic disease. She was given nothing by mouth and intravenous hydration and nutrition support was performed. Propionylglycine and 3-hydroxypropionic acid were showed high concentrations in urine by gas chromatograph mass spectrometry (GC-MS). C3 level of acylcarnitine analysis elevated 10.4 uM/L (range, 0.200-5.00) in plasma. We took gene analysis for PA to be based on the symptoms and laboratory results. We detected PCCB gene mutation and diagnosed PA. She survived without severe neurologic defects and complications and was hospitalized only three times with upper respiratory tract infections for 7 years. We report a case of a ten days old neonate with PA presenting without severe metabolic acidosis and hyperammonemia who was effectively treated with early aggressive care and conventional methods.
프로피온산혈증은 상염색체 열성유전에 의해 발생하는 질환으로, 혈중에 암모니아, 독성 물질 등이 축적되어 경한 증상에서부터 사망에까지 이르는 질환이다. 유병률은 50,000-100,000명당 1명이다. PCCA 또는 PCCB 유전자의 돌연변이로 발생하며, 이것을 규명하는 것이 가장 확실한 진단 방법이다. 두 유형에 따른 임상경과 차이는 뚜렷하게 밝혀져 있지 않다. 발병 시기에 따라 신생아기형과 후기형으로 나눌 수 있다. 증상 발현의 원인은 이화작용을 강화시키는 감염, 스트레스, 변비, 단백질의 과도한 섭취 등이며, 운동실조, 이상행동, 식욕부진, 주기적 구토, 성장장애, 신경발달이상 등의 광범위한 임상 경과를 보인다. 정확한 진단과 조속한 초기 치료가 환자의 생존율 및 신경 발달 장애 여부에 중요한 요소이다. 본 증례는 고암모니아혈증 및 대사산증이 심하지 않았으나 조기에 대사성 질환을 염두에 두고 PCCA와 PCCB 유전자의 돌연변이를 분석하여 프로피온산혈증을 진단하고 적극적인 금식 및 수액 치료와 진단을 통해 신체 발달 및 운동 및 치명적인 신경학적 장애 없이 성장한 고무적인 사례로 이를 보고하는 바이다.
