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"Yeates, Laura"
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Clinical predictors of genetic testing outcomes in hypertrophic cardiomyopathy
by
Winship, Ingrid
,
McCormack, Louise
,
Semsarian, Christopher
in
631/208/2489/1512
,
692/699/75/74
,
Adult
2013
Genetic testing for hypertrophic cardiomyopathy has been commercially available for almost a decade; however, low mutation detection rate and cost have hindered uptake. This study sought to identify clinical variables that can predict probands with hypertrophic cardiomyopathy in whom a pathogenic mutation will be identified.
Probands attending specialized cardiac genetic clinics across Australia over a 10-year period (2002–2011), who met clinical diagnostic criteria for hypertrophic cardiomyopathy and who underwent genetic testing for hypertrophic cardiomyopathy were included. Clinical, family history, and genotype information were collected.
A total of 265 unrelated individuals with hypertrophic cardiomyopathy were included, with 138 (52%) having at least one mutation identified. The mutation detection rate was significantly higher in the probands with hypertrophic cardiomyopathy with an established family history of disease (72 vs. 29%, P < 0.0001), and a positive family history of sudden cardiac death further increased the detection rate (89 vs. 59%, P < 0.0001). Multivariate analysis identified female gender, increased left-ventricular wall thickness, family history of hypertrophic cardiomyopathy, and family history of sudden cardiac death as being associated with greatest chance of identifying a gene mutation. Multiple mutation carriers (n = 16, 6%) were more likely to have suffered an out-of-hospital cardiac arrest or sudden cardiac death (31 vs. 7%, P = 0.012).
Family history is a key clinical predictor of a positive genetic diagnosis and has direct clinical relevance, particularly in the pretest genetic counseling setting.
Genet Med15 12, 972–977.
Journal Article
Genetic architecture of left ventricular noncompaction in adults
by
Driscoll, Elizabeth
,
Rajagopalan Sulekha
,
Singer, Emma S
in
Cardiomyopathy
,
Family medical history
,
Heart
2020
The genetic etiology and heritability of left ventricular noncompaction (LVNC) in adults is unclear. This study sought to assess the value of genetic testing in adults with LVNC. Adults diagnosed with LVNC while undergoing screening in the context of a family history of cardiomyopathy were excluded. Clinical data for 35 unrelated patients diagnosed with LVNC at ≥18 years of age were retrospectively analyzed. Left ventricular (LV) dysfunction, electrocardiogram (ECG) abnormalities, cardiac malformations or syndromic features were identified in 25 patients; 10 patients had isolated LVNC in the absence of cardiac dysfunction or syndromic features. Exome sequencing was performed, and analysis using commercial panels targeted 193 nuclear and mitochondrial genes. Nucleotide variants in coding regions or in intron-exon boundaries with predicted impacts on splicing were assessed. Fifty-four rare variants were identified in 35 nuclear genes. Across all 35 LVNC patients, the clinically meaningful genetic diagnostic yield was 9% (3/35), with heterozygous likely pathogenic or pathogenic variants identified in the NKX2-5 and TBX5 genes encoding cardiac transcription factors. No pathogenic variants were identified in patients with isolated LVNC in the absence of cardiac dysfunction or syndromic features. In conclusion, the diagnostic yield of genetic testing in adult index patients with LVNC is low. Genetic testing is most beneficial in LVNC associated with other cardiac and syndromic features, in which it can facilitate correct diagnoses, and least useful in adults with only isolated LVNC without a family history. Cardiac transcription factors are important in the development of LVNC and should be included in genetic testing panels.Cardiomyopathy: Genetic testing largely unhelpful for rare heart diseaseGenetic testing is of limited use for diagnosing a rare heart muscle disorder called left ventricular non-compaction (LVNC), a structural abnormality of the lower left chamber of the heart in which the muscular wall appears soft and spongy rather than smooth and compacted. A team led by Christopher Semsarian from the University of Sydney, Australia, carried out a a retrospective analysis of genetic data from 35 patients diagnosed with LVNC but with no family history of the disease. They identified only three likely pathogenic gene variants, all in known heart regulatory genes and all in individuals with symptoms of cardiac dysfunction. The researchers conclude that genetic testing can facilitate a correct diagnosis of LVNC in patients showing signs of heart problems, but is largely unhelpful for those without symptoms and no family history.
Journal Article
Using codesign focus groups to develop an online COmmunity suPporting familiEs after Sudden Cardiac Death (COPE-SCD) in the young
by
Do, Judy
,
van den Heuvel, Lieke
,
Semsarian, Christopher
in
CARDIOLOGY
,
Cardiomyopathy
,
Cardiovascular disease
2022
ObjectiveTo codesign an online support intervention for families after sudden cardiac death (SCD) in the young (<35 years).DesignCodesign of an SCD family intervention by stakeholder focus groups.SettingFamilies and healthcare professionals with experience in SCD in the young.ParticipantsSemistructured online focus groups were held with key stakeholders, that is, family members who had experienced young SCD, healthcare professionals and researchers based in New South Wales, Australia. Guided discussions were used to develop an online support intervention. Thematic analysis of discussions and iterative feedback on draft materials guided content development.ResultsFour focus groups were held (4–6 participants per group, 12 unique participants). Stakeholder involvement facilitated development of high-level ideas and priority issues. Creative content and materials were developed based on user preference for stories, narratives and information reflecting everyday experience of families navigating the legal and medical processes surrounding SCD, normalising and supporting grief responses in the context of family relationships and fostering hope. Emphasis on accessibility led to the overarching need for digital information and online engagement. These insights allowed development of an online intervention—COPE-SCD: A COmmunity suPporting familiEs after Sudden Cardiac Death—which includes a website and online support programme.ConclusionUsing codesign with stakeholders we have developed a support intervention that addresses the needs of SCD families and aims to fill a large gap in existing healthcare. We will evaluate COPE-SCD to determine whether this is an effective intervention for support of families following a young SCD.
Journal Article
The role of genetic testing in diagnosis and care of inherited cardiac conditions in a specialised multidisciplinary clinic
by
Bagnall, Richard D.
,
Nowak, Natalie
,
Ryan, Mark P.
in
Bioinformatics
,
Biomedical and Life Sciences
,
Biomedicine
2022
Background
The diagnostic yield of genetic testing for inherited cardiac diseases is up to 40% and is primarily indicated for screening of at-risk relatives. Here, we evaluate the role of genomics in diagnosis and management among consecutive individuals attending a specialised clinic and identify those with the highest likelihood of having a monogenic disease.
Methods
A retrospective audit of 1697 consecutive, unrelated probands referred to a specialised, multidisciplinary clinic between 2002 and 2020 was performed. A concordant clinical and genetic diagnosis was considered solved. Cases were classified as likely monogenic based on a score comprising a positive family history, young age at onset, and severe phenotype, whereas low-scoring cases were considered to have a likely complex aetiology. The impact of a genetic diagnosis was evaluated.
Results
A total of 888 probands fulfilled the inclusion criteria, and genetic testing identified likely pathogenic or pathogenic (LP/P) variants in 330 individuals (37%) and suspicious variants of uncertain significance (VUS) in 73 (8%). Research-focused efforts identified 46 (5%) variants, missed by conventional genetic testing. Where a variant was identified, this changed or clarified the final diagnosis in a clinically useful way for 51 (13%). The yield of suspicious VUS across ancestry groups ranged from 15 to 20%, compared to only 10% among Europeans. Even when the clinical diagnosis was uncertain, those with the most monogenic disease features had the greatest diagnostic yield from genetic testing.
Conclusions
Research-focused efforts can increase the diagnostic yield by up to 5%. Where a variant is identified, this will have clinical utility beyond family screening in 13%. We demonstrate the value of genomics in reaching an overall diagnosis and highlight inequities based on ancestry. Acknowledging our incomplete understanding of disease phenotypes, we propose a framework for prioritising likely monogenic cases to solve their underlying cause of disease.
Journal Article
Needs analysis of parents following sudden cardiac death in the young
by
Sharpe, Louise
,
McDonald, Kristie
,
Semsarian, Christopher
in
Adaptation, Psychological
,
Adolescent
,
Adult
2020
ObjectiveThe sudden cardiac death (SCD) of a young person is a devastating event for any parent. Inherited heart disease is often either identified or assumed to be the cause. Few studies have explored the psychosocial impact to the surviving at-risk family members. We sought to investigate the needs of parents who have experienced the SCD of their child (≤45 years).MethodsA quantitative needs analysis questionnaire was developed based on semistructured interviews, including one focus group and a review of relevant literature. Eligible participants were invited to participate in this cross-sectional survey study.ResultsThere were 38 parents who completed a quantitative survey. Parents’ perceived needs for information and support spanned medical, psychosocial, spiritual and financial domains. Of the support and information needs assessed, medical needs were identified as the most important domain, followed by psychosocial, spiritual and financial. Importantly, psychosocial information and support needs were reported as the most unmet need, endorsed by 54% of parents. Medical information and support needs were reported as unmet by almost one third of parents. The two most endorsed needs were ‘To have the option of whether or not you would pursue genetic testing for yourself or family members’ and ‘To understand what happened’.ConclusionsThis work demonstrates for the first time, the multifactorial needs of parents after SCD in the young. With the greatest unmet need reported as psychosocial needs, there is clear necessity to find ways of integrating psychological support in to the care of families after SCD in the young.
Journal Article
Relations between right ventricular morphology and clinical, electrical and genetic parameters in Brugada Syndrome
by
Bagnall, Richard D.
,
Femia, Giuseppe
,
Semsarian, Christopher
in
Abnormalities
,
Biology and Life Sciences
,
Cardiac arrhythmia
2018
Increasing evidence suggests the presence of structural changes affecting the right ventricular outflow tract (RVOT) in patients with Brugada Syndrome (BrS). The aim of this study was to characterise the RV morphology in BrS and explore associations between morphologic, clinical, electrical, and genetic parameters using non-invasive multimodality testing.
Consecutive BrS patients (recruited 2013-2015) underwent clinical assessment, dedicated RV imaging using cardiac magnetic resonance (CMR) imaging (unless contra-indicated), electrical assessment (electrocardiogram, Holter monitoring, signal-averaged ECG[SAECG]) and genotyping. Morphologic data were compared to matched control and unmatched ARVC (arrhythmogenic right ventricular cardiomyopathy) cohorts, and potential associations between morphologic parameters and other variables were explored.
BrS patients (n = 42, male 86%, age 46±12 years) exhibited normal global RV volume and function, comparable to control, in contrast to significantly larger, impaired RVs in ARVC cohort (RVESV p = 0.0001; RVEDV p<0.0001, RVEF p = 0.002). Compared with control, BrS patients exhibited larger RVOT volumes (7.4 ± 0.7 vs 5.8 ± 0.7 mL/m2, p<0.0001) and wall motion abnormalities (RWMA) (31% vs 0%, p = 0.005); compared with ARVC cohort, the RVOT volumes were similar (7.4 ± 0.7 vs, 8.1 ± 1.7, p = 0.52) and there were less RWMA (31% vs 76%, p = 0.01). Overall 67% BrS patients had abnormal RVOT morphology. Patients with abnormal RVOT tended to be older (48 ± 12 y vs 41 ± 12y, p = 0.06). Rare genetic variants were only observed in patients with abnormal RVOT morphology (36% vs 0%, p = 0.02).
Patients with BrS frequently exhibit structural abnormalities localised to the RVOT and these changes may be age- and gene-dependent.
Journal Article
Risk of Sudden Death and Outcome in Patients With Hypertrophic Cardiomyopathy With Benign Presentation and Without Risk Factors
by
Bongioanni, Sergio
,
Boni, Luca
,
Formisano, Francesco
in
Aged
,
Analysis of Variance
,
Atrial Fibrillation - mortality
2014
Patients with hypertrophic cardiomyopathy (HC) are reported to have a mortality rate of about 1.0% per year, and those patients without sudden death risk factors and with no or mild symptoms are generally considered to have a benign clinical presentation. However, the risk of sudden death and the outcome in this latter subgroup have not been investigated systematically and remain unresolved. We assessed the risk of sudden death and outcome in 653 consecutive patients with HC without risk factors and with no or mild symptoms. Over a median follow-up of 5.3 years, 35 patients (5.4%) died of HC-related causes. Mean age at death was 46 ± 20 years in patients who died suddenly and 66 ± 15 and 72 ± 9 years, respectively, in patients who died of heart failure or stroke. Event rate was 0.6% per year for sudden death, 0.2% per year for heart failure death, and 0.1% per year for stroke-related death. Sudden death risk was independently and inversely related to age, and risk of heart failure or stroke death was directly related to age (p = 0.020). At 10 years after the initial evaluation, sudden death risk was 5.9%, with sudden death rate being the lowest (0.3% per year) in patients with normal left atrial dimension (≤40 mm). In conclusion, in patients with HC without conventional risk factors and with no or mild symptoms, the risk of sudden death was not negligible, with an event rate of 0.6% per year. Heart failure and stroke-related death were less common and largely confined to older patients. These results underscore the need for a more accurate assessment of the sudden death risk in patients with HC.
Journal Article
Comparison of conventional autopsy and magnetic resonance imaging in determining the cause of sudden death in the young
2014
Background
Sudden death in the young is a tragic complication of a number of medical diseases. There is limited data regarding the utility of post-mortem Magnetic Resonance (MR) imaging and Computer Tomography (CT) scanning in determining the cause of sudden death. This study sought to compare the accuracy of post-mortem cross-sectional imaging (MR and CT) with the conventional autopsy in determining the cause of sudden death in the young.
Methods
Consecutive patients from 2010 to 2012 (aged 1–35 years) who had sudden death were included. Patients were scanned by CT and 1.5 T MR imaging prior to the conventional autopsy being performed. The primary outcome was diagnostic congruence between imaging and conventional autopsy.
Results
In 17 patients studied, the mean age at death was 23 ± 11 years, with a male predominance (n = 12; 71%). The most common cause of death was a primary cardiac pathology (n = 8; 47%), including ARVC (24%) and ischemic heart disease (12%). Non-cardiac causes identified included pulmonary embolism (6%), and aortic dissection (6%). MR imaging correctly identified the diagnosis in 12 patients who subsequently had positive findings at conventional autopsy, while the diagnosis in the remaining 5 cases remained unexplained. MR imaging was found to be highly sensitive (100%) with a high negative (100%) and positive (80%) predictive value.
Conclusions
Dedicated post-mortem MR imaging of the heart and brain is a useful modality in determining the cause of sudden death in children and young adults, particularly in situations where a conventional autopsy cannot be performed for logistic, cultural or personal reasons.
Journal Article
Overcoming the challenges of studying conservation physiology in large whales: a review of available methods
by
Kraus, Scott D.
,
Yeates, Laura C.
,
Rowles, Teresa K.
in
Anthropogenic factors
,
Aquatic mammals
,
Biopsy
2013
A description and comparison of the four major methods available for studying conservation physiology of large whales, namely analysis of faecal, respiratory vapour, and skin/blubber biopsy samples, and photographs.AbstractLarge whales are subjected to a variety of conservation pressures that could be better monitored and managed if physiological information could be gathered readily from free-swimming whales. However, traditional approaches to studying physiology have been impractical for large whales, because there is no routine method for capture of the largest species and there is presently no practical method of obtaining blood samples from free-swimming whales. We review the currently available techniques for gathering physiological information on large whales using a variety of non-lethal and minimally invasive (or non-invasive) sample matrices. We focus on methods that should produce information relevant to conservation physiology, e.g. measures relevant to stress physiology, reproductive status, nutritional status, immune response, health, and disease. The following four types of samples are discussed: faecal samples, respiratory samples (‘blow’), skin/blubber samples, and photographs. Faecal samples have historically been used for diet analysis but increasingly are also used for hormonal analyses, as well as for assessment of exposure to toxins, pollutants, and parasites. Blow samples contain many hormones as well as respiratory microbes, a diverse array of metabolites, and a variety of immune-related substances. Biopsy dart samples are widely used for genetic, contaminant, and fatty-acid analyses and are now being used for endocrine studies along with proteomic and transcriptomic approaches. Photographic analyses have benefited from recently developed quantitative techniques allowing assessment of skin condition, ectoparasite load, and nutritional status, along with wounds and scars from ship strikes and fishing gear entanglement. Field application of these techniques has the potential to improve our understanding of the physiology of large whales greatly, better enabling assessment of the relative impacts of many anthropogenic and ecological pressures.
Journal Article
Cold Stress Induces an Adrenocortical Response in Bottlenose Dolphins (Tursiops truncatus)
by
Crocker, Daniel E.
,
Yeates, Laura C.
,
Houser, Dorian S.
in
aldosterone
,
Aldosterone - blood
,
Ambient temperature
2011
Two adult bottlenose dolphins (Tursiops truncatus) were individually housed in aboveground pools over a 10-day period and exposed to decreasing water temperatures to determine whether cold stress activated the hypothalamic-pituitary-adrenal axis. To serve as controls, two additional adult dolphins were similarly housed for the same duration but at ambient water temperatures (16.8–19.6°C). Across all subjects, water temperatures ranged from 4.2 to 19.6°C. Voluntary blood draws were made from each dolphin every 2–3 days, and serum was analyzed via radioimmunoassay for cortisol and aldosterone. Dolphins exposed to cold water showed an increase in serum cortisol and aldosterone as temperature declined; at the coldest water exposure, cortisol was more than three times and aldosterone more than two times the levels measured at ambient temperature. Elevations occurred before the water temperature declined below the individual animal's lower critical temperature, the point at which the metabolic rate increases to compensate for the loss of body heat. Variations in corticosteroids were unrelated to the 10-day isolation period, suggesting that the response was related to the cold stress and not impacted by the isolation. Elevations in cortisol and aldosterone were lower than those observed in force captured and stranded dolphins. Although potentially related to the general adaptive stress response, elevations in cortisol and aldosterone may have other adaptive functions related to mitigating impacts resulting from cold environmental temperatures.
Journal Article