Search

Key Points: Question: Does the rare variant genetic architecture of dilated cardiomyopathy differ between patients of African and European ancestry? Findings: In this cross-sectional study of 1198 patients with dilated cardiomyopathy, significantly fewer patients of African ancestry (8.2%) than those European ancestry (25.5%) had variants classified as pathogenic or likely pathogenic, a difference due in part to fewer predicted loss-of-function variants and less case-based evidence to support pathogenicity for variants found only in patients of African ancestry. Meaning: Assumptions regarding dilated cardiomyopathy genetic architecture derived from European ancestry may not be applicable to African ancestry; a current lack of case data limits clinical genetics care for patients of African ancestry with dilated cardiomyopathy. Importance: Black patients with dilated cardiomyopathy (DCM) have increased familial risk and worse outcomes than White patients, but most DCM genetic data are from White patients. Objective: To compare the rare variant genetic architecture of DCM by genomic ancestry within a diverse population of patients with DCM. Design: Cross-sectional study enrolling patients with DCM who self-identified as non-Hispanic Black, Hispanic, or non-Hispanic White from June 7, 2016, to March 15, 2020, at 25 US advanced heart failure programs. Variants in 36 DCM genes were adjudicated as pathogenic, likely pathogenic, or of uncertain significance. Exposure: Presence of DCM. Main Outcomes and Measures: Variants in DCM genes classified as pathogenic/likely pathogenic/uncertain significance and clinically actionable (pathogenic/likely pathogenic). Results: A total of 505, 667, and 26 patients with DCM of predominantly African, European, or Native American genomic ancestry, respectively, were included. Compared with patients of European ancestry, a lower percentage of patients of African ancestry had clinically actionable variants (8.2% [95% CI, 5.2%-11.1%] vs 25.5% [95% CI, 21.3%-29.6%]), reflecting the lower odds of a clinically actionable variant for those with any pathogenic variant/likely pathogenic variant/variant of uncertain significance (odds ratio, 0.25 [95% CI, 0.17-0.37]). On average, patients of African ancestry had fewer clinically actionable variants in TTN (difference, −0.09 [95% CI, −0.14 to −0.05]) and other genes with predicted loss of function as a disease-causing mechanism (difference, −0.06 [95% CI, −0.11 to −0.02]). However, the number of pathogenic variants/likely pathogenic variants/variants of uncertain significance was more comparable between ancestry groups (difference, −0.07 [95% CI, −0.22 to 0.09]) due to a larger number of non-TTN non–predicted loss of function variants of uncertain significance, mostly missense, in patients of African ancestry (difference, 0.15 [95% CI, 0.00-0.30]). Published clinical case-based evidence supporting pathogenicity was less available for variants found only in patients of African ancestry (P <.001). Conclusion and Relevance: Patients of African ancestry with DCM were less likely to have clinically actionable variants in DCM genes than those of European ancestry due to differences in genetic architecture and a lack of representation of African ancestry in clinical data sets. This study compares the rare variant genetic architecture of dilated cardiomyopathy (DCM) among patients with DCM who are of African ancestry compared with European ancestry. [ABSTRACT FROM AUTHOR]

Background: Managing disease risk among first-degree relatives of probands diagnosed with a heritable disease is central to precision medicine. A critical component is often clinical screening, which is particularly important for conditions like dilated cardiomyopathy (DCM) that remain asymptomatic until severe disease develops. Nonetheless, probands are frequently ill-equipped to disseminate genetic risk information that motivates at-risk relatives to complete recommended clinical screening. An easily implemented remedy for this key issue has been elusive. Methods: The DCM Precision Medicine Study developed Family Heart Talk , a booklet designed to help probands with DCM communicate genetic risk and the need for cardiovascular screening to their relatives. The effectiveness of the Family Heart Talk booklet in increasing cardiovascular clinical screening uptake among first-degree relatives was assessed in a multicenter, open-label, cluster-randomized, controlled trial. The primary outcome measured in eligible first-degree relatives was completion of screening initiated within 12 months after proband enrollment. Because probands randomized to the intervention received the booklet at the enrollment visit, eligible first-degree relatives were limited to those who were alive the day after proband enrollment and not enrolled on the same day as the proband. Results: Between June 2016 and March 2020, 1241 probands were randomized (1:1) to receive Family Heart Talk (n=621) or not (n=620) within strata defined by site and self-identified race/ethnicity (non-Hispanic Black, non-Hispanic White, or Hispanic). Final analyses included 550 families (n=2230 eligible first-degree relatives) in the Family Heart Talk arm and 561 (n=2416) in the control arm. A higher percentage of eligible first-degree relatives completed screening in the Family Heart Talk arm (19.5% versus 16.0%), and the odds of screening completion among these first-degree relatives were higher in the Family Heart Talk arm after adjustment for proband randomization stratum, sex, and age quartile (odds ratio, 1.30 [1-sided 95% CI, 1.08–∞]). A prespecified subgroup analysis did not find evidence of heterogeneity in the adjusted intervention odds ratio across race/ethnicity strata (P =0.90). Conclusions: Family Heart Talk , a booklet that can be provided to patients with DCM by clinicians with minimal additional time investment, was effective in increasing cardiovascular clinical screening among first-degree relatives of these patients. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03037632. [ABSTRACT FROM AUTHOR]

OBJECTIVE. Antenatal hydronephrosis is diagnosed in 1% to 5% of all pregnancies; however, the antenatal and postnatal management of hydronephrosis varies widely. No previous studies define the risk of postnatal pathology in infants with antenatal hydronephrosis. Our objective was to review the current literature to determine whether the degree of antenatal hydronephrosis and related antenatal ultrasound findings are associated with postnatal outcome. METHODS. We searched Medline (1966-2005), Embase (1991-2004), and the Cochrane Library databases for articles on antenatal hydronephrosis. We required studies to have subjects selected on the basis of documented measurements of antenatal hydronephrosis and followed to a postnatal diagnosis. We excluded case reports, review articles, and editorials. Two independent investigators extracted data. RESULTS. We screened 1645 citations, of which 17 studies met inclusion criteria. We created a data set of 1308 subjects. The risk of any postnatal pathology per degree of antenatal hydronephrosis was 11.9% for mild, 45.1% for moderate, and 88.3% for severe. There was a significant increase in risk per increasing degree of hydronephrosis. The risk of vesicoureteral reflux was similar for all degrees of antenatal hydronephrosis. CONCLUSIONS. The findings of this meta-analysis can potentially be used for prenatal counseling and may alter current postnatal management of children with antenatal hydronephrosis. Overall, children with any degree of antenatal hydronephrosis are at greater risk of postnatal pathology as compared with the normal population. Moderate and severe antenatal hydronephrosis have a significant risk of postnatal pathology, indicating that comprehensive postnatal diagnostic management should be performed. Mild antenatal hydronephrosis may carry a risk for postnatal pathology, but additional prospective studies are needed to determine the optimal management of these children. A well-defined prospective analysis is needed to further define the risk of pathology and the appropriate management protocols. Key Words hydronephrosis, renal, kidney disease, prenatal, outcome Abbreviations ANH--antenatal hydronephrosis VCUG--voiding cystourethrogram APD--anterior posterior diameter UPJ--ureteropelvic junction obstruction VUR--vesicoureteral reflux CI--confidence interval, ANTENATAL HYDRONEPHROSIS (ANH) affects ~1% to 5% of all pregnancies and is one of the most common birth defects. (1-4) However, the reported clinical relevance of varying degrees of ANH [...]

BACKGROUND. Newborn screening programs now identify children with >30 biochemical genetic disorders. False-positive identifications may increase as disorders are added to screening panels. Concerns arise regarding the potential impact on parental stress, family relationships, and perceptions of the child&apos;s health. METHODS. Parents of 173 infants with false-positive screening results for a biochemical genetic disorder in the expanded newborn screening panel were compared with parents of 67 children with normal screening results. Parents completed an interview that elicited information about demographic features, child and parental health, and understanding of newborn screening. Parents also completed the parenting stress index. RESULTS. Parents in the false-positive group attained higher total scores on the PSI than did parents in the normal-screened group, scoring higher on the parent-child dysfunction subscale and the difficult child subscale. Only approximately one third of parents in the false-positive group reported knowing the correct reason for repeat screening. Mothers who reported knowing the correct reason for their child&apos;s repeat screening test experienced less total stress than did mothers who were misinformed, were not informed, or did not remember. CONCLUSIONS. False-positive screening results may affect parental stress and the parent-child relationship. Improved communication with parents regarding the need for repeat screening tests may reduce the negative impact of false-positive results. Key Words newborn screening, false-positive, parental stress, vulnerable child, nocebo phenomenon, parent-child relationship Abbreviations PKU--phenylketonuria PSI--parenting stress index, RECENT EXPANSION OF newborn screening for biochemical genetic disorders has led not only to an increase in positive identifications but also to a dramatic increase in false-positive test results. A [...]

Cerebellar hemorrhage (CBH) in premature infants is increasingly diagnosed secondary to improved neuroimaging techniques and survival of very small preterm infants. Information is limited, however, on the incidence, topography, and risk factors for CBH in the preterm infant. Objectives. To define the incidence of CBH in preterm infants diagnosed by neonatal cranial ultrasound (US), describe the sonographic features of CBH, and identify maternal and perinatal risk factors associated with this lesion. Methods. A systematic electronic database search identified preterm infants born 1998-2002 with US diagnosis of CBH. For 35 cases of CBH we double-matched (according to gestational age, gender, and year of birth) 70 preterm controls with normal cranial USs and performed detailed medical-record reviews for both patients and controls. Results. Unilateral CBH was seen in 25 patients (71%), vermian hemorrhage was seen in 7 (20%), and combined bihemispheric and vermian hemorrhage was seen in 3 (9%). Isolated CBH occurred in 8 patients (23%); the remaining infants had associated supratentorial lesions. The incidence of CBH in preterm infants weighing Conclusions. CBH is an important complication of extreme preterm birth and has been underrecognized in surviving preterm infants. Predictors of CBH seem to be multifactorial and include combined maternal, intrapartum, and early postnatal factors. Pediatrics 2005;116:717-724; cerebellar hemorrhage, premature infants, cranial ultrasound, incidence, risk factors., ABBREVIATIONS. CBH, cerebellar hemorrhage; US, ultrasound/ ultrasonographic; GM-IVH, germinal matrix-intraventricular hemorrhage; PVHI, periventricular hemorrhagic infarction; PDA, patent ductus arteriosus; BPD, bronchopulmonary dysplasia; OR, odds ratio; CI, confidence interval. Hemorrhage into [...]

Importance: Idiopathic dilated cardiomyopathy (DCM) aggregates in families, and early detection in at-risk family members can provide opportunity to initiate treatment prior to late-phase disease. Most studies have included only White patients, yet Black patients with DCM have higher risk of heart failure-related hospitalization and death.Objective: To estimate the prevalence of familial DCM among DCM probands and the age-specific cumulative risk of DCM in first-degree relatives across race and ethnicity groups.Design, Setting, and Participants: A family-based, cross-sectional study conducted by a multisite consortium of 25 US heart failure programs. Participants included patients with DCM (probands), defined as left ventricular systolic dysfunction and left ventricular enlargement after excluding usual clinical causes, and their first-degree relatives. Enrollment commenced June 7, 2016; proband and family member enrollment concluded March 15, 2020, and April 1, 2021, respectively.Exposures: The presence of DCM in a proband.Main Outcomes and Measures: Familial DCM defined by DCM in at least 1 first-degree relative; expanded familial DCM defined by the presence of DCM or either left ventricular enlargement or left ventricular systolic dysfunction without known cause in at least 1 first-degree relative.Results: The study enrolled 1220 probands (median age, 52.8 years [IQR, 42.4-61.8]; 43.8% female; 43.1% Black and 8.3% Hispanic) and screened 1693 first-degree relatives for DCM. A median of 28% (IQR, 0%-60%) of living first-degree relatives were screened per family. The crude prevalence of familial DCM among probands was 11.6% overall. The model-based estimate of the prevalence of familial DCM among probands at a typical US advanced heart failure program if all living first-degree relatives were screened was 29.7% (95% CI, 23.5% to 36.0%) overall. The estimated prevalence of familial DCM was higher in Black probands than in White probands (difference, 11.3% [95% CI, 1.9% to 20.8%]) but did not differ significantly between Hispanic probands and non-Hispanic probands (difference, -1.4% [95% CI, -15.9% to 13.1%]). The estimated prevalence of expanded familial DCM was 56.9% (95% CI, 50.8% to 63.0%) overall. Based on age-specific disease status at enrollment, estimated cumulative risks in first-degree relatives at a typical US advanced heart failure program reached 19% (95% CI, 13% to 24%) by age 80 years for DCM and 33% (95% CI, 27% to 40%) for expanded DCM inclusive of partial phenotypes. The DCM hazard was higher in first-degree relatives of non-Hispanic Black probands than non-Hispanic White probands (hazard ratio, 1.89 [95% CI, 1.26 to 2.83]).Conclusions and Relevance: In a US cross-sectional study, there was substantial estimated prevalence of familial DCM among probands and modeled cumulative risk of DCM among their first-degree relatives.Trial Registration: ClinicalTrials.gov Identifier: NCT03037632. [ABSTRACT FROM AUTHOR]

Precision medicine genetics study design requires large, diverse cohorts and thoughtful use of electronic technologies. Involving patients in research design may increase enrollment and engagement, thereby enabling a means to relevant patient outcomes in clinical practice. Few data, however, illustrate attitudes of patients with dilated cardiomyopathy (DCM) and their family members toward genetic study design. This study assessed attitudes of 16 enrolled patients and their family members (P/FM), and 18 investigators or researchers (I/R) of the ongoing DCM Precision Medicine Study during a conjoint patient and investigator meeting using structured, self‐administered surveys examining direct‐to‐participant enrollment and web‐based consent, return of genetic results, and other aspects of genetic study design. Survey respondents were half women and largely identified as white. Web‐based consent was supported by 93% of P/FM and 88% of I/R. Most respondents believed that return of genetic results would motivate study enrollment, but also indicated a desire to opt out. Ideal study design preferences included a 1‐hour visit per year, along with the ability to complete study aspects by telephone or web and possibility of prophylactic medication. This study supports partnership of patients and clinical researchers to inform research priorities and study design to attain the promise of precision medicine for DCM. [ABSTRACT FROM AUTHOR]

Refined estimates of risk based on genetic risk modifiers could assist BRCA mutation carriers in understanding their risk, but it is not clear whether carriers are interested in receiving these estimates or how they might benefit from them. Using qualitative interviews, we investigated female BRCA1 and BRCA2 mutation carriers' (N = 20) reactions to numerical and verbal presentations of breast cancer risk based on risk modifiers and assessed women's preferences regarding visual formats for communicating risk. Our results show carriers are interested in receiving refined risk estimates and suggest the estimates may influence decision-making regarding cancer prevention, depending on the nature of the risk assessment. Although accurate and precise estimates of breast cancer risk are most important to women, they preferred quantitative risk estimates expressed as a proportion with or without a population comparison; however, women noted that comparisons to other BRCA mutation carriers were less useful given their high risk. Participants also preferred communication of a risk as a specific percentage versus a range of risk, but a clear preference regarding visual displays was not expressed. Results support many existing recommendations for genetic risk communication and provide guidance for the development of tools incorporating genetic risk modifiers. [ABSTRACT FROM AUTHOR]

Background: The hypothesis of the Dilated Cardiomyopathy Precision Medicine Study is that most dilated cardiomyopathy has a genetic basis. The study returns results to probands and, when indicated, to relatives. While both the American College of Medical Genetics and Genomics/Association for Molecular Pathology and ClinGen's MYH7 -cardiomyopathy specifications provide relevant guidance for variant interpretation, further gene- and disease-specific considerations were required for dilated cardiomyopathy. To this end, we tailored the ClinGen MYH7 -cardiomyopathy variant interpretation framework; the specifications implemented for the study are presented here., Methods: Modifications were created and approved by an external Variant Adjudication Oversight Committee. After a pilot using 81 probands, further adjustments were made, resulting in 27 criteria (9 modifications of the ClinGen MYH7 framework and reintroduction of 2 American College of Medical Genetics and Genomics/Association of Molecular Pathology criteria that were deemed not applicable by the ClinGen MYH7 working group)., Results: These criteria were applied to 2059 variants in a test set of 97 probands. Variants were classified as benign (n=1702), likely benign (n=33), uncertain significance (n=71), likely pathogenic (likely pathogenic; n=12), and pathogenic (P; n=3). Only 2/15 likely pathogenic/P variants were identified in Non-Hispanic African ancestry probands., Conclusions: We tailored the ClinGen MYH7 criteria for our study. Our preliminary data show that 15/97 (15.5%) probands have likely pathogenic/P variants, most of which were identified in probands of Non-Hispanic European ancestry. We anticipate continued evolution of our approach, one that will be informed by new insights on variant interpretation and a greater understanding of the genetic architecture of dilated cardiomyopathy., Clinical Trial Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03037632.

Family-based designs have been commonly used in association studies. Different family structures such as extended pedigrees and nuclear families, including parent-offspring triads and families with multiple affected siblings (multiplex families), can be ascertained for family-based association analysis. Flexible association tests that can accommodate different family structures have been proposed. The pedigree disequilibrium test (PDT) (Martin et al., Am J Hum Genet 67:146-154, 2000) can use full genotype information from general (possibly extended) pedigrees with one or multiple affected siblings but requires parental genotypes or genotypes of unaffected siblings. On the other hand, the association in the presence of linkage (APL) test (Martin et al., Am J Hum Genet 73:1016-1026, 2003) is restricted to nuclear families with one or more affected siblings but can infer missing parental genotypes properly by accounting for identity-by-descent (IBD) parameters. Both the PDT and APL test are powerful association tests in the presence of linkage and can be used as complementary tools for association analysis. This chapter introduces these two tests and compares their properties. Recommendations and notes for performing the tests in practice are provided.

The hydration of fat-free mass, or hydration fraction (HF), is often defined as a constant body composition parameter in a two-compartment model and then estimated from in vivo measurements. We showed that the widely used estimator for the HF parameter in this model, the mean of the ratios of measured total body water (TBW) to fat-free mass (FFM) in individual subjects, can be inaccurate in the presence of additive technical errors. We then proposed a new instrumental variables estimator that accurately estimates the HF parameter in the presence of such errors. In Monte Carlo simulations, the mean of the ratios of TBW to FFM was an inaccurate estimator of the HF parameter, and inferences based on it had actual type I error rates more than 13 times the nominal 0.05 level under certain conditions. The instrumental variables estimator was accurate and maintained an actual type I error rate close to the nominal level in all simulations. When estimating and performing inference on the HF parameter, the proposed instrumental variables estimator should yield accurate estimates and correct inferences in the presence of additive technical errors, but the mean of the ratios of TBW to FFM in individual subjects may not.