SLC25A13 and neonatal intrahepatic cholestasis due to citrin deficiency: Although a maternally originated SLC25A13 mutation IVS16ins3kb had been discovered as a high-frequency mutation in this study, conventional genetic analyses, such as PCR/LA-PCR, PCR-RFLP, and Sanger sequencing, could not unveil the paternally inherited mutation in the infant with typical clinical and biochemical features of intrahepatic cholestasis, making the definite diagnosis of NICCD a challenge.