PRKAG2 and disorder of glycogen metabolism: The pathogenic variants of the PRKAG2 gene identified are mainly related to missense variants and inframe indels, mainly related to the WPWS phenotype alone or associated with hypertrophic cardiomyopathy and the phenotype of autosomal-dominant familial hypertrophic cardiomyopathy type 6 secondary to nonlysosomal glycogenosis during late adolescence or early adulthood.