There are several phenotypes of HCM: asymmetric (septal), apical, symmetric, mass-like, midventricular, and noncontiguous. Most often, cases of midventricular HCM are reported in the context of midventricular obstruction with associated apical aneurysm formation. Echocardiogram in this case demonstrated no evidence of dynamic obstruction as a result of the mid-cavity thickening, and there was no apical aneurysm present.
The patient was diagnosed with midventricular HCM (nonobstructive subtype). Genetic testing demonstrated mutations in the MYPN and SCN5A genes. While these are not the most common genetic mutations found in HCM, the former is a known association 5 while the latter has been seen in at least one case of familial HCM 6.