For families ED168 and ED241, across the exome the MPLKIP splice mutation is the only rare homozygous variant that is predicted to be deleterious or damaging and this variant segregates with both TTDN and mitral regurgitation, supporting the inclusion of cardiomyopathy as a feature of TTDN due to MPLKIP variants. This evidence concerns the gene MPLKIP and mitral valve insufficiency.