Genetic evidence of subaortic stenosis in the Newfoundland dog

Abstract

Subaortic stenosis (SAS) is a cardiac disorder with a narrowing of the descending aorta below the left ventricular outflow tract of the heart. It occurs in several species and breeds. The Newfoundland is one of the dog breeds where it is more common and usually leads to death at early adulthood. It is still discussed to which extent SAS has a genetic background and what its mode of inheritance could be. Extensive pedigree data comprising more than 230,000 Newfoundland dogs from the European and North American population reaching back to the 19th century including 6023 dogs with a SAS diagnosis were analysed for genetic factors influencing SAS affection. The incidence and prevalence of SAS in the analysed Newfoundland population sample were much higher than those reported in previous studies on smaller population samples. Assuming that some SAS-affected dogs remained undiscovered or were not reported, these figures may even be underestimated. SAS-affected Newfoundland dogs were more often inbred and closer related to each other than unaffected dogs, which is an indicator for a genetic background of SAS. The sex had no significant impact on SAS affectedness, pointing at an autosomal inheritance. The only simple mode of inheritance that fitted the data well was autosomal codominant with lethal homozygosity and a penetrance of 1/3 in the heterozygotes.

Insights into Morphology and Disease from the Dog Genome Project

“…Heart disease is observed in many dog breeds (Parker et al 2006), from dilated cardiomyopathy in the Doberman Pinscher (Steudemann et al 2013) to subaortic stenosis in Newfoundlands (Reist-Marti et al 2012), Golden Retrievers (Stern et al 2012), and Dogue de Bordeaux dogs (Ohad et al 2013). Congestive heart failure is observed in many breeds (Isono et al 2012), as are cardiomyopathy (Mausberg et al 2011, Meurs et al 2012, Owczarek-Lipska et al 2013b), ventricular arrhythmia ( Jesty et al 2013), and mitral valve disease (Fox 2012, French et al 2012).…”

Balloon valvuloplasty for severe subaortic stenosis in a Pomeranian dog

“…pressure overload, mortality is likely associated with the degree of left ventricular concentric hypertrophy, development of microvascular disease, and resultant ischemia, which may be associated with sudden death or clinical signs in SAS dogs [5,8]. Therefore, normalized cTnI in this case would suggest possible role of balloon valvuloplasty in improved clinical sign and reduced pressure overload of severe SAS despite of minimal pressure gradient reduction.…”

“…In dogs with congenital SAS, high cTnI level may be an indicator of cardiac injury from microvascular disease and subsequent ischemia [8]. In this case, 2 specific findings (ST segment change of electrocardiogram and ultrasonic hyperechogenicity of the myocardium) were interpreted as indicators of ischemic damage.…”

Surgical Interventions of Common Congenital Heart Defects in Dogs: A Comprehensive Review

“…The dog breeds such as Newfoundland are with more common subaortic stenosis which usually leads to an early death [20] . Subaortic stenosis has been genetically evidenced as an autosomal inheritance in Newfoundland dog [20] .…”

“…The dog breeds such as Newfoundland are with more common subaortic stenosis which usually leads to an early death [20] . Subaortic stenosis has been genetically evidenced as an autosomal inheritance in Newfoundland dog [20] . A study on 195 untreated dogs with subaortic stenosis showed that sudden death was associated with severe subaortic stenosis 16 times more than moderate or mild, which often developed within the first three years of life [21] .…”