Chronic pancreatitis (CP) is a progressive fibroinflammatory syndrome of the pancreatic tissue caused by genetic and environmental factors. Previously reported susceptibility genes in CP explain less than half of the apparent heritability. To uncover novel pathogenic mechanisms, we initially performed low-coverage whole-genome sequencing on 464 Chinese CP patients and 504 controls. The transient receptor potential cation channel, Subfamily V, Member 6 (TRPV6) gene was found to be significantly associated with CP after a burden test of aggregated rare nonsynonymous variants with a combined annotation dependent depletion score > 20 (p = .020). In the replication stage, we analyzed the entire coding sequence and exon/intron boundaries of the TPRV6 gene by Sanger sequencing in another 205 patients with CP and 105 controls. Integration of the findings from the two stages resulted in the identification of 25 TRPV6 variants: 1 rare nonsense variant, 20 rare missense variants, and 4 common missense variants. Loss-of-function variants, as determined by intracellular Ca2+ concentration in transfected HEK293T cells, were significantly overrepresented in patients as compared to controls (9/669 [1.35%] vs. 1/609 [0.16%]; odds ratio = 8.29; p = .022). This study provides evidence suggesting that TRPV6 is a novel susceptibility gene for CP.
Keywords: TRPV6 gene; calcium signaling; chronic pancreatitis; low-coverage whole-genome sequencing; missense variants.
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