Hypertrophic cardiomyopathy is clinically defined by the presence of increased left ventricular (LV) wall thickness that is not solely explained by abnormal loading conditions. The aetiology is diverse, but in 60% of patients the disease is an autosomal dominant trait caused by cardiac sarcomere protein gene mutation (HCM). In 10% of cases, the cause is inherited metabolic and neuromuscular disease, chromosomic abnormalities and genetic syndromes, whereas, in the remaining 30% of patients the aetiology remains unknown.

We are indebted to Maja Cikes, MD, PhD from University of Zagreb for her contributions to this line of research and her continuous support to the authors. This work was partially supported by Spanish Ministry of Economy and Competitiveness (grant TIN2014-52923-R; Maria de Maeztu Units of Excellence Programme - MDM-2015-0502), FEDER, Grants from Fundacio La Marató de TV3 (040310) and Horizon 2020 European Commission Project H2020-MSCA-ITN-2016 (764738).