Objective:To explore the relationship between arrhythmogenic right ventricular cardiomyopathy (ARVC) desmosomal protein gene mutations and Yunnan unexplained sudden death (hereinafter referred to as Yunnan sudden death) by detecting 5 common ARVC desmosomal protein gene mutations of Yunnan sudden death cases and their relatives in Heqing County, Yunnan Province.Methods:In January 2021, the autopsy heart cavity blood was collected from Yunnan sudden death cases in 8 villages in Heqing County, and peripheral venous blood samples of relatives of the cases were collected. Blood samples' DNA was extracted, after PCR amplification, 97 exons of 5 desmosomal protein genes [desmoplakin (DSP), desmoglein-2 (DSG2), plakophilin-2 (PKP2), junction plakoglobin (JUP) and desmocollin-2 (DSC2)] were sequenced by Sanger method to analyze gene mutations.Results:Three blood samples of Yunnan sudden death cases and 36 blood samples of relatives were collected. A total of 26 gene mutation sites were detected in 39 blood samples, with a total mutation rate of 26.80% (26/97). There were 13, 5, 3, 3 and 2 mutation sites in DSP, DSG2, PKP2, JUP and DSC2 genes, respectively. Among them, 19 were reported mutations and 7 were new mutations: DSP gene exon 3 c.372G>A, exon 15 c.2090A>G, exon 17 c.2371C>A, exon 24-I c.8458T>G; DSG2 gene exon 8 c.861C>T; PKP2 gene exon 3 c.892C>A, exon 8 c.1725G>T. Three Yunnan sudden death cases and 36 relatives were all carriers of compound gene mutation, and the same person carried 3 - 9 gene mutation sites at the same time.Conclusion:Mutations of ARVC desmosomal protein genes DSP, DSG2, PKP2, JUP and DSC2 exist in Yunnan sudden death cases and their relatives, which may be the genetic background factors of some Yunnan sudden death.