KLF13 Loss-of-Function Mutations Underlying Familial Dilated Cardiomyopathy

Background Dilated cardiomyopathy (DCM), characterized by progressive left ventricular enlargement and systolic dysfunction, is the most common type of cardiomyopathy and a leading cause of heart failure and cardiac death. Accumulating evidence underscores the critical role of genetic defects in the pathogenesis of DCM, and >250 genes have been implicated in DCM to date. However, DCM is of substantial genetic heterogeneity, and the genetic basis underpinning DCM remains elusive in most cases. Methods and Results By genome-wide scan with microsatellite markers and genetic linkage analysis in a 4-generation family inflicted with autosomal-dominant DCM, a new locus for DCM was mapped on chromosome 15q13.1-q13.3, a 4.77-cM (≈3.43 Mbp) interval between markers D15S1019 and D15S1010, with the largest 2-point logarithm of odds score of 5.1175 for the marker D15S165 at recombination fraction (θ)=0.00. Whole-exome sequencing analyses revealed that within the mapping chromosomal region, only the mutation in the KLF13 gene, c.430G>T (p.E144X), cosegregated with DCM in the family. In addition, sequencing analyses of KLF13 in another cohort of 266 unrelated patients with DCM and their available family members unveiled 2 new mutations, c.580G>T (p.E194X) and c.595T>C (p.C199R), which cosegregated with DCM in 2 families, respectively. The 3 mutations were absent from 418 healthy subjects. Functional assays demonstrated that the 3 mutants had no transactivation on the target genes ACTC1 and MYH7 (2 genes causally linked to DCM), alone or together with GATA4 (another gene contributing to DCM), and a diminished ability to bind the promoters of ACTC1 and MYH7. Add, the E144X-mutant KLF13 showed a defect in intracellular distribution. Conclusions This investigation indicates KLF13 as a new gene predisposing to DCM, which adds novel insight to the molecular pathogenesis underlying DCM, implying potential implications for prenatal prevention and precision treatment of DCM in a subset of patients.