Aim: To investigate XPNPEP1 rs17095355 polymorphism in biliary atresia (BA) patients and to determine whether there is an association between XPNPEP1 gene polymorphism and susceptibility to BA in a Thai population.
Methods: A total of 124 cases of BA and 114 controls were genotyped for XPNPEP1 rs17095355 polymorphism. The XPNPEP1 rs17095355 C/T genotype was determined by polymerase chain reaction (PCR) and direct sequencing. Allele and genotype frequencies were established by directed counting from the sequences.
Results: Genotype distributions for the XPNPEP1 rs17095355 polymorphism tested were in Hardy–Weinberg equilibrium for both control and study groups. There were no significant differences in genotype and allele frequencies of the single nucleotide polymorphism between controls and Thai children with BA. Genotype frequencies of rs17095355 of T/T in BA were higher than those of controls (34.68% and 16.67%, P < 0.002). Also, the T allele frequencies of BA were higher than those of controls (56.85% and 42.98%, P < 0.003).
Conclusion: The association between XPNPEP1 rs17095355 polymorphism and BA has been demonstrated, particularly with the T allele. We hypothesize that the XPNPEP1 rs17095355 polymorphism confers increased susceptibility to the disease.