One cat (Case 6) was diagnosed with hypertrophic cardiomyopathy (HCM) and had a positive NT-proBNP test result (Table 1), with systemic blood pressure of 150 mmHg and normal serum thyroid hormone concentration of 2.1 μg/dL (reference range, 0.6–3.9 μg/dL). This evidence concerns the gene NPPB and hypertrophic cardiomyopathy.