Introduction

We aimed to evaluate the association of microRNA-499 rs3746444 polymorphism and biliary atresia (BA) risk and its correlation with clinic-pathologic features of BA.

Material and methods

This study was performed on 300 Egyptian children (100 BA cases, 100 cases with cholestatic liver diseases other than BA and 100 healthy controls). Routine laboratory investigations, clinical examination and abdominal ultrasound were done. All infants were genotyped for miR-499 single nucleotide polymorphisms (SNPs) (rs3746444 A>G) by real-time polymerase chain reaction (PCR) fluorescence detection on a Rotor Gene Real Time PCR System (QIAGEN, GmbH) using fluorescent labeled probes.

Results

The AG genotype was the most prevalent genotype of miR-499 rs3746444 among the studied groups. A significantly higher frequency of the rs3746444 G allele was found in the BA cases than the other groups (odds ratio = 1.62). This polymorphism was also correlated with the degree of fibrosis in BA cases (p < 0.05). The miR-499 rs3746444 polymorphism (GG genotype) was significantly associated with severe form of BA and bad prognosis after the Kasai operation (p < 0.05). miR-499 rs3746444 polymorphism had no effect on the clinic-pathological features or the liver function status in the non-BA group.

Conclusions

There is an association between the miR-499 SNP genotypes and the occurrence of BA. The variant allele G is the predominant allele in the BA group and is associated with severe liver inflammation and bad prognosis after the Kasai operation.