TTN and overlapping connective tissue disease: Only isolated reports showed causal mutations in non-desmosomal genes, such as transmembrane protein 43 (TMEM43), desmin (DES), titin (TTN), Lamin A/C (LMNA), phospholamban (PLN) and αT-catenin (CTNNA3), sometimes with a clinical phenotype similar but not identical to AC, as to be considered phenocopies or overlap syndromes [51–56].