title: Diagnosis of neonatal intrahepatic cholestasis caused by citrin deficiency using high-resolution melting analysis and a clinical scoring system.
abstract: OBJECTIVE
  To assess the diagnosis of neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) by using high-resolution melting (HRM) analysis and a clinical scoring system.
  
  
  METHODS
  Genetic variations in the 18 coding exons were prescreened using HRM analysis and then confirmed by direct sequencing. To establish a scoring system, clinical features of 20 patients with NICCD diagnosed in Taiwan between the years 2000 and 2008 were compared with those of 47 patients with biliary atresia and 35 with infantile cholestasis.
  
  
  RESULTS
  Eight types of mutations/polymorphisms were identified in patients with NICCD, including 5 mutations in the coding region or splice site (c.851del4, c.1638ins23, R553Q, IVS6+5G > A, IVS11+1G > A), and 3 single-nucleotide polymorphisms (IVS11+17C > G, IVS4+6A > G/rs6957975, and c.1194A > G/rs2301629). The 3 hotspot mutations (c.851del4, c.1638ins23, and IVS6+5G > A) comprised 33/35 (94.3%) mutated alleles. The patients with NICCD had a higher frequency of the rs6957975 polymorphism compared with 103 healthy controls (P < .0001). A 6-point scoring system was proposed according to clinical parameters. The patients with NICCD tended to score ≥ 4 points, whereas biliary atresia and other infantile cholestasis tended to score <4 points (P < .0001).
  
  
  CONCLUSIONS
  HRM analysis was efficient and effective in detecting mutations. Three common mutations comprised the majority of mutations found in our patients. The IVS4+6A > G polymorphism was associated with NICCD. A scoring system may help to differentiate patients with NICCD from those with biliary atresia.
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital Yun-Lin Branch, Yun-Lin County, Taiwan.
authors.forename: Szu-Ta
authors.initials: ST
authors.lastname: Chen
authors.forename: Yi-Ning
authors.initials: YN
authors.lastname: Su
authors.forename: Yen-Hsuan
authors.initials: YH
authors.lastname: Ni
authors.forename: Wuh-Liang
authors.initials: WL
authors.lastname: Hwu
authors.forename: Ni-Chung
authors.initials: NC
authors.lastname: Lee
authors.forename: Yin-Hsiu
authors.initials: YH
authors.lastname: Chien
authors.forename: Cheng-Chi
authors.initials: CC
authors.lastname: Chang
authors.forename: Huey-Ling
authors.initials: HL
authors.lastname: Chen
authors.forename: Mei-Hwei
authors.initials: MH
authors.lastname: Chang
mesh_terms: D020159:Citrullinemia / Q000175:diagnosis* / Q000235:genetics; D005787:Gene Frequency; D006801:Humans; D007231:Infant, Newborn; D033681:Mitochondrial Membrane Transport Proteins / Q000235:genetics; D009154:Mutation; D020125:Mutation, Missense; D009691:Nucleic Acid Denaturation; D020641:Polymorphism, Single Nucleotide
chemical_list: D033681:Mitochondrial Membrane Transport Proteins; C119629:SLC25A13 protein, human