Subaortic stenosis is a narrowing of the left ventricular outflow tract just below the aortic valve, and is one ofthe most diagnosed congenital inherited heart diseases in the Newfoundland. The classification of subaortic stenosisis based on the lesions or the findings on echocardiography. Although the mode of inheritance is uncertain, a dominanttrait with variable penetrance is generally accepted. The Epidermal Growth Factor Receptor oncogene is, togetherwith the Ptpn11-gene, a possible candidate gene to be involved in this disease. The diagnosis is particulary based onauscultation and echocardiography. The prognosis is variable and breeding advice is based on echocardiographicscreening at the age of eighteen months; however, it remains a difficult issue.