Clinical and genetic features of neonatal intrahepatic cholestasis caused by citrin deficiency in northern China: A single-center analysis of 23 cases / 临床肝胆病杂志

ABSTRACT

ObjectiveTo investigate the clinical features and gene mutation characteristics of neonatal intrahepatic cholestasis caused citrin deficiency (NICCD) in northern China. MethodsA total of 23 pediatric patients in northern China who were diagnosed with NICCD by blood tandem mass spectrometry and/or gene detection in Department of Gastroenterology, Children’s Hospital Affiliated to Capital Institute of Pediatrics, from January 2015 to December 2018 were enrolled as NICCD group, and 36 pediatric patients with idiopathic neonatal cholestasis (INC) who had unclarified etiology after a series of examinations during the same period of time were enrolled as INC group. A retrospective analysis was performed for the clinical manifestation, laboratory examination, pathology, blood/urine metabolic screening, and gene sequencing results of the pediatric patients in the NICCD group, and follow-up was performed to observe their outcome; biochemical parameters were compared between the two groups. The independent samples t-test was used for comparison of normally distributed continuous data, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data; the chi-square test was used for comparison of categorical data between groups. ResultsAmong the 23 patients in the NICCD group, 10 had hypoglycemia, 13 had hypoalbuminemia, 17 had hyperammonemia, and 15 had hyperlactacidemia; 15 had an increase in low-density lipoprotein, 6 had an increase in cholesterol, and 7 had an increase in triglyceride; 17 had prolonged prothrombin time, and 16 had prolonged activated partial thromboplastin time (APTT). Compared with the INC group, the NICCD group had significantly higher gamma-glutamyl transpeptidase (GGT), total bile acid (TBA), and APTT and a significantly lower albumin (Alb) level (Z=-2.487, Z=-3.528, t=3.532, t=-2.24, all P＜0.05). For the patients with NICCD, blood tandem mass spectrometry showed that the most common abnormalities were the increased levels of arginine, citrulline, methionine, free carnitine, and long-chain acylcarnitine, while urinary gas chromatography showed the increased levels of 4-hydroxyphenyllactic acid, galactose, galactitol, and galactonic acid. Gene detection was performed for all 23 patients and identified 16 pathogenic mutations, among which 7 were newly discovered, namely ivs14-9a＞G, c1640 G＞A, c.762T＞A, c.736delG, c.1098 T del, c.851G＞A, and c.550G＞A. Except for the 2 patients who were lost to follow-up, the levels of aminotransferases and bilirubin gradually returned to normal in 21 patients after 2-6 months of treatment; none of them showed delayed growth and development after being followed up to the age of 1 year, and 2 of them developed dietary preference (they liked fish and meat and did not like staple food). ConclusionAbnormalities of blood GGT, TBA, Alb, and APTT may provide ideas for the differential diagnosis of NICCD and INC. NICCD gene mutations in northern China are heterogeneous and most patients tend to have a good prognosis.