Citrullinemia type II accompanied by mental derangement combined with multidrug resistance 3 decrease, case report

Here we report a rare case of citrullinemia type II (CTLN2) accompanied by mental derangement with a deficiency of multidrug resistance 3 (MDR3) in the liver. The clinical data of a 17-year-old girl were collected. Liver puncture was performed, and hepatic expression of MDR3 was determined by immunohistochemistry. Serum amino acids of the patient and her parents wwere determined by a chemical isotope labeling liquid chromatography−mass spectrometry (CIL LC-MS). Genetic mutations of ABCB4 and SLC25A13 were screened by whole-exome sequencing. Immunohistochemical analysis showed a remarkably lower expression of MDR3. Mutation in ABCB4 gene was not found and whole-exome sequencing revealed the SLC25A13 mutation 852–855 del. Elevated serum levels of citrulline, homocitrulline, and homoarginine in the patient and her mother were found. We reported a rare case of CTLN2 combined with MDR3 deficiency, without mutation of ABCB4. The link between MDR3 down-expression and CTLN2 warrants further investigation. Meanwhile, clinicians need to further rule out the possibility of CTLN2 if MDR3 decreases in adolescent patients with mental disorders and abnormal liver function. •This case of CTLN2 presented mental disorders and abnormal liver function.•Immunohistochemical analysis showed a remarkably lower expression of MDR3.•Whole-exome sequencing revealed the SLC25A13 mutation 852–855 del3.