Cardiomyopathy With Preexcitation and Conduction Abnormalities in a Child

An 11-year-old boy presented with dilated cardiomyopathy in association with a fasciculoventricular pathway and sinus node and atrioventricular conduction abnormalities. Whole exome sequencing revealed a novel variant of uncertain significance in LIM domain-binding protein 3 (LDB3) which has not been heretofore described. This variant was predicted to be deleterious by the computational prediction tools: Polyphen2 and SIFT. The mutated allele was heterozygous in the patient. Segregation analysis revealed that his father carried the same variant in heterozygous form. The case is reported for its rarity.