BACKGROUND: APOLT has been proposed as a treatment modality for certain types of NCMLD. While the short-term outcomes of this operation have been comparable with orthotopic LT, its long-term outcomes have sparsely been reported. We present one such case of Citrullinemia type I who underwent APOLT and developed recurrent PS.
METHODS: A 2-year-old male child with a diagnosis of Citrullinemia type I underwent APOLT with a left lateral segment from a split deceased donor liver, and his postoperative period was unremarkable. Ammonia-lowering agents were stopped 1 week following the operation and the child was discharged home on a normal diet. Four years following APOLT, the child presented with altered sensorium and seizures. A diagnosis of PS was made. Subsequent to an embolization of the native liver\'s right anterior portal vein his sensorium improved and he remained clinically stable on a normal diet. Six years following the APOLT, the child again presented with features of acute encephalopathy. Imaging was suggestive of PS. A portal vein embolization of the native portal vein was performed and the child\'s clinical condition improved. At 6 months\' follow-up, the child remains well on a normal diet.
CONCLUSIONS: While the early impediments in this technique may have been overcome, in the absence of any realistic clinical application gene therapy, the debate of long-term phenotypic metabolic correction for NCMLD by APOLT needs to be revisited.

Over the past decade, the ASS1 and SLC25A13 genes, which are responsible for citrullinemia types I and II, have been identified, and numerous mutations in these genes have been reported. The clinical manifestations of citrullinemia are quite heterogeneous, and most studies have reported mutations in a small number of patients from a few families. Comprehensive integration of previous knowledge is important to understand the mutation spectrum and effect of the mutations on clinical manifestations. Therefore, we reviewed the English literature on mutations in the ASS and SLC25A13 genes, and their genotype-phenotype correlations to provide valuable insights into the molecular genetic background of citrullinemia types I and II.

Type II citrullinaemia, also known as citrin deficiency, is an autosomal recessive metabolic disorder, which is caused by pathogenic mutations in the SLC25A13 gene on chromosome 7q21.3. One of the clinical manifestations of type II citrullinaemia is neonatal intrahepatic cholestatic hepatitis caused by citrin deficiency (NICCD, OMIM# 605814). In this study, a 5-month-old female Chinese neonate diagnosed with type II citrullinaemia was examined. The diagnosis was based on biochemical and clinical findings, including organic acid profiling using a gas chromatography mass spectrometry (GC/MS), and the patient\'s parents were unaffected. Approximately 14 kb of the exon sequences of the SLC25A13 and two relative genes (ASS1 and FAH) from the proband and 100 case-unrelated controls were captured by array-based capture method followed by high-throughput next-generation sequencing. Two single-nucleotide mutations were detected in the proband, including the previous reported c.1177+1G>A mutation and a novel c.754 G>A mutation in the SLC25A13 gene. Sanger sequence results showed that the patient was a compound heterozygote for the two mutations. The novel mutation (c.754 G>A), which is predicted to affect the normal structure and function of citrin, is a candidate pathogenic mutation. Target sequence capture combined with high-throughput next-generation sequencing technologies is proven to be an effective method for molecular genetic testing of type II citrullinaemia.