The distribution and common amino acid polymorphisms of human papillomavirus (HPV)-31 variants in 2700 women from Northern China

Abstract

To investigate the distribution of Human papillomavirus (HPV)-31 A, B and C variants as well as the common amino acid polymorphisms in Chinese women, all 14 HPV-31 positive cervical exfoliated cell specimens identified from a descriptive study including ∼2700 women from Northern China were analyzed. HPV-31 positive specimens were identified by Mass Spectrometry and the fragments of partial Long Control Region, E6 and E7 were amplified and directly sequenced or cloned into vector and then sequenced to confirm the variant information. HPV-31 prevalence in Northern Chinese female population was 0.52%. Six different sequences represented all 14 isolates, and these isolates were subsequently classified into variant lineage A (9), B (0) and C (5) by phylogenetic analysis. Five common amino acid polymorphism sites (2 in E6 and 3 in E7) and a novel non-synonymous mutation were detected in the current study. Our investigation suggested that HPV-31 was much less detected in Chinese women population than that in western countries. A and C variants were commonly detected while B variants were rarely detected in this population.

Figure 1. The Neighborhood Joining phylogenetic tree of HPV-31 variants.

The tree was constructed using HPV-31 variants sequences of partial Long Control Region, E6 and E7 identified in Northern China (NC specimens, N = 6) and variants previously reported in whole genome study (N = 19) . Numbers on the nodes indicated the bootstrap values (1000 replicates) of branches. ^* NC_001527 was the reference sequence of HPV-31 and it was not one of the sequences identified in the current study. ^† The sequence of NC-27H9 was the same as IN221709.