Abstract
To investigate the relationship of multidrug resistance 3 (Mdr3) gene mutation and parenteral nutrition-associated cholestasis (PNAC) in preterm infants. Preterm infants who had received total parenteral nutrition for at least 14 days were enrolled: 76 preterm infants in the PNAC group and 80 preterm infants in the non-PNAC group. Genomic DNA was extracted from white blood cells. Twenty-eight exons of the Mdr3 gene were amplified by polymerase chain reaction. PNAC infants of 1 month corrected age with the Mdr3 gene mutation and abnormal liver biochemistry were selected for the experimental liver biopsy group. Five normal adult living liver transplantation donors were enrolled in a normal donor group. The Mdr3 missense mutations c.1031G>A, c.3347G>A, and c.485T>A, and the Mdr3 frameshift mutation c.2793_2794insA were found in the PNAC group. The allele frequency and genotype frequency of c.1031G>A, c.3347G>A, and c.485T>A in the Mdr3 gene in the PNAC group were significantly higher than those in non-PNAC group (p < 0.05). The rate of Mdr3 gene mutations c.1031G>A, c.485T>A, c.3347G>A, and c.2793_2794insA in the PNAC group was higher than in the non-PNAC group (21.05% vs. 1.25%, respectively, χ(2) = 15.747, p < 0.05). Mdr3 gene mutations c.2793_2794insA, c.1031G>A, c.3347G>A, and c.485T>A may be the genetic cause of PNAC.