Evaluation of Rare and Common Variants from Suspected Familial or Sporadic Nasopharyngeal Carcinoma (NPC) Susceptibility Genes in Sporadic NPC

Background: Genetic susceptibility is associated with nasopharyngeal carcinoma (NPC). We previously identified rare variants potentially involved in familial NPC and common variants significantly associated with sporadic NPC. Methods: We conducted targeted gene sequencing of 20 genes [16 identified from the study of multiplex families, three identified from a pooled analysis of NPC genome-wide association study (GWAS), and one identified from both studies] among 819 NPC cases and 938 controls from two case-control studies in Taiwan (independent from previous studies). A targeted, multiplex PCR primer panel was designed using the custom Ion AmpliSeq Designer v4.2 targeting the regions of the selected genes. Gene-based and single-variant tests were conducted. Results: We found that NPC was associated with combined common and rare variants in CDKN2A/2B (P = 1.3 x 10(-4)), BRD2 (P = 1.6 x 10(-3)), TNFRSF19 (P = 4.0 x 10(-3)), and CLPTM1L/TERT (P = 5.4 x 10(-3)). Such associations were likely driven by common variants within these genes, based on gene-based analyses evaluating common variants and rare variants separately (e.g., for common variants of CDKN2A/2B, P = 4.6 x 10(-4); for rare variants, P = 0.04). We also observed a suggestive association with rare variants in HNRNPU (P = 3.8 x 10(-3)) for NPC risk. In addition, we validated four previously reported NPC risk-associated SNPs. Conclusions: Our findings confirm previously reported associated variants and suggest that some common variants in genes previously linked to familial NPC are associated with the development of sporadic NPC. Impact: NPC-associated genes, including CLPTM1L/TERT, BRD2, and HNRNPU, suggest a role for telomere length maintenance in NPC etiology.