A Novel In-Frame Deletion in the Kcnq1 Gene and An Akap9 Variant in Iranian Patients With Long-Qt Syndrome

Background and aim: congenital long-qt syndrome represents a heterogeneous disorder leading primarily to sudden cardiac death (scd) in the young. two symptomatic patients with a family history of eight scds in an iranian pedigree prompted us to identify and characterize the underlying genetic basis.methods: whole exome sequencing and dna sanger sequencing were performed for genotype determination of the patients. different predictive tools followed by family study were employed for the pathogenicity prediction of the variants.results: a reported heterozygous variant (rs139965373) in akap9 gene was identified by whole exome sequencing but a novel in-frame deletion in the kcnq1 gene (c.40_55delcgctggggttggggc) was revealed through dna sanger sequencing. the latter was detected in all patients but none of the healthy family members.conclusion: identification of the novel mutation in iranian patients not only supports the genetic modifier effect of the akap9 variant but also indicates the next generation sequencing disadvantage as an opening and exclusive method for the genetic diagnosis of long-qt syndrome.