A single codon insertion in PICALM is associated with development of familial subvalvular aortic stenosis in Newfoundland dogs.

Familial subvalvular aortic stenosis (SAS) is one of the most common congenital heart defects in dogs and is an inherited defect of Newfoundlands, golden retrievers and human children. Although SAS is known to be inherited, specific genes involved in Newfoundlands with SAS have not been defined. We hypothesized that SAS in Newfoundlands is inherited in an autosomal dominant pattern and caused by a single genetic variant. We studied 93 prospectively recruited Newfoundland dogs, and 180 control dogs of 30 breeds. By providing cardiac screening evaluations for Newfoundlands we conducted a pedigree evaluation, genome-wide association study and RNA sequence analysis to identify a proposed pattern of inheritance and genetic loci associated with the development of SAS. We identified a three-nucleotide exonic insertion in phosphatidylinositol-binding clathrin assembly protein (PICALM) that is associated with the development of SAS in Newfoundlands. Pedigree evaluation best supported an autosomal dominant pattern of inheritance and provided evidence that equivocally affected individuals may pass on SAS in their progeny. Immunohistochemistry demonstrated the presence of PICALM in the canine myocardium and area of the subvalvular ridge. Additionally, small molecule inhibition of clathrin-mediated endocytosis resulted in developmental abnormalities within the outflow tract (OFT) of Xenopus laevis embryos. The ability to test for presence of this PICALM insertion may impact dog-breeding decisions and facilitate reduction of SAS disease prevalence in Newfoundland dogs. Understanding the role of PICALM in OFT development may aid in future molecular and genetic investigations into other congenital heart defects of various species.

The occurrence and suspected mode of inheritance of congenital subaortic stenosis and tricuspid valve dysplasia in Dogue de Bordeaux dogs.

The Dogue de Bordeaux (DdB) breed has gone through several genetic 'bottle necks' and has a relatively small effective population size. Importing new stock into Israel has been limited, further narrowing the already restricted local gene-pool and increasing the chances of inherited defects. In 56 DdB dogs examined between 2003 and 2010, the authors sought to study the proportion congenital subaortic stenosis (SAS) and tricuspid valve dysplasia (TVD). The aim was also to identify a probable mode of inheritance (MOI) using segregation and pedigree analyses of genealogical data available from 13/21 DdB dogs diagnosed with these conditions between 2004 and 2007. Among all breeds in the country, TVD was highest in the DdB breed, which also displayed the second highest proportion of SAS. Echocardiographic measurements and selected physical examination findings from 26 normal DdB dogs, 18 DdB dogs with SAS, and 12 DdB dogs with TVD are reported. Based on pedigree and segregation analyses, the most probable MOI appeared to be autosomal recessive. Pedigree analyses helped to identify three ancestors that might have introduced these two congenital heart defects into the local DdB population. Excluding those three dogs and their progeny from future mating could therefore reduce the prevalence of these diseases in the DdB population in Israel. The unusual local breeding circumstances may offer a unique opportunity to identify associated SAS and TVD genes in the DdB, as well as in other dog breeds.

[Subvalvular aortic stenosis associated with 8p23 deletion]. / Estenose aórtica subvalvular associada à deleção 8p23.

We report the case of a 35-year-old man admitted due to heart failure, who had had moderate cognitive deficit, craniofacial dysmorphism, epilepsy, panic attacks and congenital heart disease (subvalvular aortic stenosis) associated with chronic atrial fibrillation since childhood. In view of his facial dysmorphism and clinical presentation, karyotype analysis was performed and revealed a de novo interstitial deletion in chromosome 8 in the region p23.1-p23.2. This is a rare chromosomal anomaly (about 50 descriptions in the literature), whose most common manifestations include heart defects, cognitive retardation and behavioral disturbances. In this paper we present the first case with associated subvalvular aortic stenosis and review the literature on this chromosomal abnormality.

Genetic evidence of subaortic stenosis in the Newfoundland dog.

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.

Familial subvalvular aortic stenosis in golden retrievers: inheritance and echocardiographic findings.

OBJECTIVES: To describe the echocardiographic findings and pedigree analysis of golden retrievers with subvalvular aortic stenosis. METHODS: Seventy-three golden retrievers were evaluated by auscultation and echocardiography. A subcostal continuous-wave Doppler aortic velocity ê2·5 m/s and presence of a left basilar systolic ejection murmur were required for diagnosis of subvalvular aortic stenosis. Three echocardiographic characteristics were recorded: evidence of aortic insufficiency, subvalvular ridge or left ventricular hypertrophy. A disease status score was calculated by totalling the number of echocardiographic -characteristics per subject. RESULTS: Thirty-two of 73 dogs were affected and their aortic velocities were as follows: range 2·5 to 6·8 m/s, median 3·4 m/s and standard deviation 1·2 m/s. Echocardiographic characteristics of 32 affected dogs were distributed as follows: left ventricular hypertrophy 12 of 32, aortic insufficiency 20 of 32 and subvalvular ridge 20 of 32. Disease status score ranged from 0 to 3 with a median of 2. There was a statistically significant correlation between aortic velocity and disease status score (r=0·644, P<0·0001). Subvalvular aortic stenosis was observed in multiple generations of several families and appears familial. CLINICAL SIGNIFICANCE: Subvalvular aortic stenosis in the golden retriever is familial. Severity of stenosis correlates well with cumulative presence of echocardiographic characteristics (left ventricular hypertrophy, subvalvular ridge and aortic insufficiency).

The relevance of echocardiography heart measures for breeding against the risk of subaortic and pulmonic stenosis in Boxer dogs.

The aims of this study were to investigate the role and relative importance of auscultation and echocardiography traits as risk factors for the diagnosis of subaortic (SubAS) and pulmonic (PS) stenosis and to estimate the heritability (h(2)) of cardiac measurements taken through echocardiography for a random sample of Italian Boxer dogs. The data were cardiovascular examination results of 1,283 Italian Boxer dogs (686 females and 597 males) enrolled in the national screening program for heart defects arranged by the Italian Boxer Club. Examinations were performed during a 6-yr period by a group of 7 veterinary cardiologists following a standard protocol. Occurrence and severity of SubAS and PS were diagnosed, taking into account clinical and echocardiography findings such as the grade of cardiac murmur, direct ultrasound imaging of the anatomic obstructive lesions, and values of aortic or pulmonary blood flow velocities. A Bayesian logistic regression analysis was performed to identify clinical and echocardiography variables related to SubAS and PS diagnosis. Estimation of variance components for clinical and echocardiography traits was performed using a mixed linear animal model, Bayesian procedures, and the Gibbs sampler. Prevalence of SubAS (PS) was 8.4% (2.2) and 10.7% (6.4) for female and male dogs, respectively. Cardiac murmur, peak velocities, and annulus areas behaved as risk factors for SubAS and PS. The risk of a positive diagnosis for SubAS was 3 times greater for dogs with aortic annulus area <2.1 cm(2) relative to dogs with areas >2.37 cm(2), 84 times greater for dogs showing aortic peak velocities >2.19 m/s relative to dogs with peak velocities <1.97 m/s, and 41 times greater for dogs with moderate to severe murmur grades relative to dogs with absent murmur. Similar results were obtained for PS. The estimated h(2) for the occurrence of cardiac defects was 23.3% for SubAS and 8.6% for PS. Echocardiography and cardiac murmur grades exhibited moderate h(2) estimates and exploitable additive genetic variation. The estimated h(2) was 36, 24, and 20% for aortic annulus area, aortic peak velocity, and cardiac murmur score, respectively. For the area of the pulmonary annulus and peak pulmonary velocity, the estimated h(2) were smaller, ranging from 9.5 to 12.8%. These measures are candidate indicator traits that might be effectively used in dog breeding to reduce the prevalence and severity of cardiac defects.

3q29 interstitial microdeletion syndrome: an inherited case associated with cardiac defect and normal cognition.

An inherited, interstitial subtelomere deletion of approximately 1.3-1.4 Mb at 3q29 was identified in a patient and his father utilizing BAC array comparative genomic hybridization (a-CGH). The imbalance was located within the common 3q29 microdeletion syndrome region and shared the distal breakpoint with prior published cases. However, our patient was developmentally normal at 6 months of age and his father is a functional adult, who had mild developmental delay in childhood. They presented with congenital cardiac defects including patent ductus arteriosus. In addition, the patient had subvalvular aortic stenosis and his father had pulmonic stenosis. These defects were not present in most of the previously reported 3q29 microdeletion cases. This case expands the phenotypic findings associated with 3q29 microdeletion syndrome, suggesting an association with cardiac defect. It also raises the possibility of normal cognition in adulthood.

Familial bilateral blepharoptosis and subvalvular aortic stenosis.

A boy and his mother with bilateral congenital blepharoptosis, downslanting palpebral fissures, hypertelorism, microcephaly, short nose with flattened nasal root, microstomia, prominent lateral palatine ridges, bifid (boy) hypoplastic (mother) uvula, generalized dental caries, short neck, peculiar voice and mild conductive deafness are reported. The boy had subvalvular aortic stenosis. The mother had pectus excavatum but not any signs or symptoms of cardiovascular defect.

Familial occurrence of discrete subaortic membrane.

The first case of multiple family members with discrete subaortic membrane and no other congenital defects is presented. One family member presents with findings suggesting a forme fruste of this disease. Increased surveillance of family members of individuals with discrete subaortic membrane is warranted, as the clinical findings of mild subaortic obstruction may be indistinguishable from those of an innocent flow murmur.

Supravalvular aortic stenosis associated with a deletion disrupting the elastin gene.

Supravalvular aortic stenosis (SVAS) is an inherited vascular disease that can cause heart failure and death. SVAS can be inherited as an autosomal dominant trait or as part of a developmental disorder, Williams syndrome (WS). In recent studies we presented evidence suggesting that a translocation disrupting the elastin gene caused SVAS in one family while deletions involving the entire elastin locus caused WS. In this study, pulsed-field, PCR, and Southern analyses showed that a 100-kb deletion of the 3' end of the elastin gene cosegregated with the disease in another SVAS family. DNA sequence analysis localized the breakpoint between elastin exons 27 and 28, the same region disrupted by the SVAS-associated translocation. These data indicate that mutations in the elastin gene cause SVAS and suggest that elastin exons 28-36 may encode critical domains for vascular development.

Familial fixed subaortic stenosis.

In this report, we give details of two families in which fixed subaortic stenosis was found in more than one member. It is rare for this entity to show familial incidence.

[Chromosome aberrations in children with the Williams-Beuren syndrome]. / Chromozómové aberácie u detí s Williamsovým-Beurenovým syndrómom.

Karyotypic examinations were carried out in 10 children suffering from Williams-Beuren's syndrome. Chromosomal aberrations were established in two of the children. In one case the mosaic pattern of Klinefelter's syndrome was recorded, evidently presenting an instance of coincidence. In the other case deletion of the long arm of chromosome 6 (q22.2q23) was demonstrated, which according to the authors' hypothesis may represent an alternative localization of the phenotypic traits of Williams-Beuren's syndrome or of its assumed underlying defect, namely derangement of the regulation of calcium metabolism. The value of cytogenetic examination of children with Williams-Beuren's syndrome in elucidating the so far obscure pathogenesis of this disease is being emphasized.

Autosomal dominant supravalvular aortic stenosis: large three-generation family.

Supravalvular aortic stenosis (SVAS) can be inherited as an isolated autosomal dominant trait or can be a component manifestation of the Williams syndrome. Some consider the Williams syndrome to be due to more severe expression of the gene defect that causes isolated SVAS. We describe a family with isolated SVAS that is the largest thoroughly studied family with this disorder to our knowledge; no patients in this family had Williams syndrome. Five members of this family were reported by Lewis et al. (Dis Chest 55:372-379, 1969). We reevaluated this family and now include examinations of the parents, additional sibs and children of the original 5 patients. Twenty relatives had physical and echocardiographic examinations. In addition, information from outside sources was obtained on 7 relatives not personally evaluated. The SVAS showed marked variability of expression and was not associated with mental retardation or with the facial manifestations of Williams syndrome. We think that previous reports of Williams syndrome reputedly occurring within the same family as isolated autosomal dominant SVAS were inadequately documented. Based on our family and review of the literature, we suggest that isolated SVAS and Williams syndrome represent clinically distinct entities.

[Supravalvular aortic stenosis. Autosomal dominant form of congenital cardiopathy]. / La sténose aortique supravalvulaire forme dominante autosomique de cardiopathie congénitale.

We describe a family in which two generations are affected: two brothers and one of their maternal uncles. One of their two half-sisters (same mother) is also suspected of having the same cardiopathy. This observation confirms the autosomal dominant transmission of the disease and shows its variable expressivity in the family under study.

Familial membranous subaortic stenosis.

Familial occurrence of membranous subaortic stenosis (MSS) is described in three families. The defect was found in 2 siblings in two of these families, and in 3 siblings of the third family. The importance of early diagnosis and treatment of MSS is emphasized. We suggest early evaluation of first-degree relatives of patients with MSS for the possibility of this defect.

Discrete subaortic stenosis as part of a short stature syndrome.

Observations in a family point to the existence of autosomal dominant inheritance for discrete subaortic stenosis (DSS), which made up part of a multisystem disorder. Both parents, offspring of two full siblings, had short stature, obstructive lung disease (OLD), hoarseness and upturned nose. The father alone had aortic stenosis and inguinal hernia. The six offspring, aged from 13 to 28 years, were followed up for up to 8 years. While one of them was virtually normal, and one had only minor abnormalities, four siblings displayed clinical signs of progressive aortic stenosis. Of the two eldest siblings who eventually died, necropsy in one showed a discrete subaortic stenosis, which was hemodynamically proven in one and surgically corrected in another sibling. Upturned nose was present in each examined member of the family, short stature and hoarseness in five of the siblings, DSS in four, OLD, inguinal hernia and congested episcleral veins in three, kyphoscoliosis in two, while epicanthus, strabismus, microphthalmos and widely spaced teeth were noted in the deceased female. The prevalence of some of these traits in roughly three-quarters of the sibship was consistent with an underlying single gene abnormality in affected heterozygous parents. We proposed that this constitutes a new syndrome.

Noninvasive diagnosis of the cardiomyopathies.

The presenting clinical features of the cardiomyopathies are nonspecific. Echocardiography is useful in detecting patients with cardiomyopathy and determining proper management. Echocardiography can be used to determine both cardiac structural measurements and cardiac function.