본 연구는 심한 발현 양상을 보인 NICCD 환자의 임상상과 그들의 분자 유전학적 결과를 고찰하여, NICCD의 빠른 진단 및 치료를 통해 임상 경과의 호전을 관찰하였기에 이를 보고하는 바이다. 신생아 광범위 대사 이상 질환 스크리닝 검사의 보편화와 더불어 NICCD 환자들의 진단 수는 앞으로 지속적으로 증가할 것으로 보이며, 이들의 장기적인 경과 관찰을 통한 예후 인자 및 새로운 치료적 접근법을 도출해내야 할 것이다.
Since the causative gene, SLC25A13 which encodes citrin, was discovered in 1999, over 500 cases with citrin deficiency have been identified. Two phenotypes can occur by citrin deficiency, neonatal intrahepatic cholestasis by citrin deficiency (NICCD) and adult-onset type II citrullinemia (CTLN2). Some patients with NICCD develop CTLN2 in their later lives. Although cholestatic jaundice is spontaneously resolved within the first year of life in most cases with NICCD, a few cases experience progressive hepatic failure. In this report, two neonates with severe type of NICCD were described. Both cases exhibited neonatal cholestatic jaundice, hyperammonemia and severe coagulopathy. Of note, plasma citrulline and blood galactose levels were extremely high. Serum ${alpha}$-fetoprotein, plasma methionine, arginine, and threonine-to-serine ratio were elevated as well. SLC25A13 mutations were found in all the four alleles of both patients. With the commencement of lactose-free formula, coagulopathy and hyperammonemia were resolved, and galactose level was normalized. Currently, no factor has been identified to predict the prognosis of NICCD. More experiences are needed to build up the adequate therapeutic strategies for severe type of NICCD. Our experience, however, indicates that the degree of citrullinemia and galactosemia might reflect the severity.
