Olson, Rory J.

Abstract Pathogenic variants in cardiomyopathy genes confer substantial disease risk, yet clinical penetrance varies widely. The population-level prevalence, age-specific penetrance, and the extent to which polygenic susceptibility modifies disease risk across diverse ancestries remain poorly defined. This population-based cohort study leveraged genome sequencing and linked electronic health record data from the All of Us Research Program (n=414,830). This study found that P/LP variants in cardiomyopathy-associated genes were present in 0.91% of participants (95% CI, 0.88%–0.94%), with similar prevalence across ancestry groups. Compared with non-carriers, variant carriers had significantly higher odds of all-cause heart failure (ACHF, OR, 2.58; 95% CI, 2.31–2.89), non-ischemic heart failure (NIHF, OR, 2.74; 95% CI, 2.42–3.10), and non-ischemic cardiomyopathy (NICM, OR, 4.99; 95% CI, 4.44–5.63). Among carriers, by age 50 years, 24.5% (95% CI, 14.5%–33.4%) developed ACHF, 17.2% (95% CI, 8.8%–24.8%) developed NIHF, and 30.1% (95% CI, 19.5%–40.2%) developed NICM. Higher polygenic risk for heart failure was independently associated with increased risk of ACHF (OR, 1.81; 95% CI, 1.74–1.89), NIHF (OR, 1.66; 95% CI, 1.58–1.75), and NICM (OR, 1.69; 95% CI, 1.59–1.80). Among carriers with elevated polygenic risk, odds of disease were substantially higher than among non-carriers at average polygenic risk (ACHF: OR, 4.71; 95% CI, 4.17–5.32; NIHF: OR, 4.56; 95% CI, 3.99–5.22; NICM: OR, 8.51; 95% CI, 7.44–9.73). Results showed that P/LP variants in cardiomyopathy genes were relatively common in this large, ancestrally diverse cohort, and conferred increased risk of cardiomyopathy and HF, with incomplete but clinically meaningful penetrance. Polygenic risk for HF independently and additively increased disease risk across ancestries. Integrating both may improve risk stratification and enable more precise, equitable care.

BACKGROUND: Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder that increases risk for premature coronary artery disease and has accessible and effective interventions. The Dutch lipid clinic network is currently the most used diagnostic criterion; however, genetic sequencing provides a definitive diagnosis of FH. The goals of this study were to determine whether germline genetic screening using exome sequencing could be used to efficiently identify individuals who were genotype positive for FH. METHODS: Participants were recruited from 3 geographically and racially diverse sites in the United States (Rochester, MN; Phoenix, AZ; and Jacksonville, FL). Participants underwent Exome+ sequencing (dba Helix, San Mateo, CA) and return of results for specific genetic findings in APOB , LDLR , or PCSK9 . A chart review was performed to collect demographics, personal, and family cardiovascular history. RESULTS: At the time of the study, 84 413 participants were enrolled in the Tapestry study. Annotation and interpretation of all variants in genes for FH resulted in the identification of 419 likely pathogenic and pathogenic variants (prevalence, 0.50%), which included 116 APOB , 298 LDLR , and 5 PCSK9 . Sixty-six percent were female, the mean body mass index was 27.3, with 12.3% reporting a history of diabetes. Hypertriglyceridemia (≥150 mg/dL) was present in 39.5% and reduced HDL (<50 mg/dL) was present in 56.7% of patients. 27.5% of patients were not on cholesterol-lowering medications, and only 10% of FH carriers were at goal low-density lipoprotein cholesterol levels. A history of coronary artery disease was reported in 22.4% of the cohort. Nearly 90% of these participants were newly diagnosed carriers of FH. Only 30.8% of confirmed genetic diagnoses of FH satisfied clinical (Dutch lipid clinic network) criteria for a diagnosis. CONCLUSIONS: Our results emphasize the need for wider utilization of germline genetic sequencing for enhanced screening and detection of individuals who have familial hypercholesterolemia. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT05212428.

Background: Cardiomyopathies (CM) are a leading cause of heart failure. Identification of genetic risk preemptively may allow detection of the earliest phenotypic manifestations through implementation of interval-based cardiac screening. Previous population-based genetic screening studies have limited follow-up and inadequate phenotyping. Hypothesis: Disease penetrance of CM variants is significantly higher than previously reported. Aims: To determine the prevalence, penetrance, and disease expression of incidental CM-related genetic variants in an unselected, richly phenotyped, adult population. Methods: We analyzed a random sample of 10,000 patients from a quaternary medical center-based biobank cohort for reportable variants in 22-cardiomyopathy genes. Prioritization of genetic variants was performed using Semi-Automated Variant Interpretation, a novel software that has been previously developed and validated at our center. Prioritized variants were then manually curated by 2 independent variant interpretation specialists. Clinical phenotypes and outcomes of participants with likely pathogenic/pathogenic (LP/P) variants were determined. Results: LP/P cardiomyopathy variants were present in 1% of our cohort (n=104) within the following genes: TNNT2 (n=1), DES (n=2), LMNA (n=2), MYL2 (n=2), TNNI3 (n=2), DSG (n=4), FLNC (n=4), DSC2 (n=6), SCN5A (n=7), PKP2 (n=10), DSP (n=12), MYH7 (n=14), TTN (n=17), MYBPC3 (n=21). Only 1 participant carried two different LP/P variants. A definitive disease penetrance defined as heart failure or cardiomyopathy was found in 34% of genotype positive (G+) individuals. Possible disease penetrance defined as presence of structural heart disease identified by echocardiography was found in an additional 16% of participants (concentric left ventricular hypertrophy, diastolic dysfunction, biatrial and left atrial enlargement). Combined definitive and possible disease penetrance was found in 50% of G+ individuals. Arrhythmias and/or cardiac conduction disease (atrial fibrillation, atrioventricular block, ventricular arrhythmia) were present in 31% of G+ individuals. Conclusion: Cardiomyopathy associated LP/P variants are present in a small subset of a large quaternary medical center population as previously reported but unlike prior studies, disease penetrance manifesting as cardiac structural abnormalities and heart failure is high in G+ individuals.

Background/Objectives: Pectus excavatum (PEx) is considered, at least partially, a familial disorder. A variety of inheritance patterns, associations with genetic syndromes, and pathogenic variants have been reported. However, the etiology of this condition is still not completely understood, and no known genes have been identified as definitive contributors. Methods: Family members with a confirmed PEx diagnosis (one proband and two first-degree relatives) and non-affected members were recruited into this study. Exome sequencing was performed on all affected familial PEx cases to systematically screen for candidate genes that are likely to be causative for PEx, and on non-affected family members for variant segregation analysis. Results: Ten families, with three affected members each, participated, providing thirty familial PEx cases. Different inheritance patterns were represented across the ten pedigrees, with possible incomplete penetrance. Genetic variants in REST (essential for neuronal development and associated with pectus deformities in prior studies), SMAD4 (variants can predispose individuals to thoracic aortic diseases), and COL5A (associated with Ehlers–Danlos syndrome and Fibromuscular dysplasia) were initially identified as potentially linked to the development of pectus deformities and segregated with the phenotype. No variants were shared across families in the studied population. Conclusions: Germline exome sequencing of families with multiple individuals affected by PEx in our study identified potential gene candidates linked to PEx. These candidates are private to individual families and no strong candidates shared across multiple families were identified. These findings suggest that the inheritance of PEx may not be strongly related to a shared single genetic variant in known genes. Given the accumulating evidence for the genetic basis of familial PEx, further studies, including polygenic analyses, as well as assessment of the non-coding genome and possible epigenetic markers are warranted.

Abstract Introduction: Most rare disease patients (75 − 50%) undergoing genomic sequencing remain unsolved, often due to lack of information about variants identified. Data review over time can leverage novel information regarding disease-causing variants and genes, increasing this diagnostic yield. However, time and resource constraints have limited reanalysis of genetic data in clinical laboratories setting. We developed RENEW, (REannotation of NEgative WES/WGS) an automated reannotation procedure that uses relevant new information in on-line genetic databases to enable rapid review of genetic findings. Methods We tested RENEW in an unselected cohort of 1,066 undiagnosed cases from the Mayo Clinic Center for Individualized Medicine using new information in ClinVar, HGMD and OMIM between the date of previous analysis/testing and April of 2022. Results 5,741 variants prioritized by RENEW were rapidly reviewed by variant interpretation specialists. Mean analysis time was approximately 20 seconds per variant (32 hours total time). Reviewed cases were classified as: 879 (93.0%) undiagnosed, 63 (6.6%) putatively diagnosed, and 4 (0.4%) definitively diagnosed. Discussion New strategies are needed to enable efficient review of genomic findings in unsolved cases. We report on a fast and practical approach to address this need and improve overall diagnostic success in patient testing through a recurrent reannotation process.

AbstractAn infant was referred for evaluation of congenital glaucoma and corneal clouding. In addition, he had a pelvic kidney, hypotonia, patent ductus arteriosus, abnormal pinnae, and developmental delay. Exome sequencing identified a previously unpublished de novo single nucleotide insertion in PBX1 c.400dupG (NM_002585.3), predicted to cause a frameshift resulting in a truncated protein with loss of function (p.Ala134Glyfs*65). Identification of this loss of function variant supports the diagnosis of congenital anomalies of the kidney and urinary tract syndrome with or without hearing loss, abnormal ears, or developmental delay (CAKUTHED). Here, we propose glaucoma as an extra‐renal manifestation associated with PBX1‐related disease due to the relationship of PBX1 with MEIS1, MEIS2, and FOXC1 transcription factors associated with eye development.

AbstractNoonan syndrome (NS) is an autosomal dominant condition with variable expressivity most commonly due to a germline pathogenic variant in PTPN11, which encodes the protein tyrosine phosphatase SHP‐2. Gain‐of‐function variants in PTPN11 are known to promote oncogenic behavior in affected tissues. We report the clinical description of a young adult male presenting with relapsing ganglioneuromas, dysmorphic features, cardiac abnormalities, and multiple lentigines, strongly suspicious for NS. Solid tumor testing identified the recurrent pathogenic c.922G>A (p.Asn308Asp) in PTPN11. Proband and parental blood sampling testing confirmed c.922G>A as a de novo germline alteration. Comprehensive literature review of solid tumors specifically associated to PTPN11, indicates that this is the first documentation of ganglioneuroma and its clinical recurrence after resection in conjunction with a genetically confirmed NS diagnosis. The findings in our patient further extend the list of neuroblastic and neural crest‐derived neoplasms associated with this condition.

Significance Statement The lack of rapidly progressive murine models reflecting the more severe end of the spectrum of autosomal recessive polycystic kidney disease (ARPKD) inhibits progress to understanding ARPKD pathogenesis. Defects in primary cilia have been implicated in polycystic kidney disease, but their potential role is poorly understood. The authors generated and characterized new mouse and rat models of ARPKD and autosomal dominant polycystic kidney disease (ADPKD) and investigated the interaction between causative genes for these two conditions. Their digenic models demonstrated a synergistic interaction that better reflects the early-onset disease characteristic of ARPKD. Analysis of mRNA expression in the models highlighted different disrupted pathways, but with a commonality of dysregulated mechanisms associated with primary cilia. These models may improve understanding of ARPKD and preclinical testing for this disease. Background Autosomal recessive polycystic kidney disease (ARPKD) and autosomal dominant polycystic kidney disease (ADPKD) are genetically distinct, with ADPKD usually caused by the genes PKD1 or PKD2 (encoding polycystin-1 and polycystin-2, respectively) and ARPKD caused by PKHD1 (encoding fibrocystin/polyductin [FPC]). Primary cilia have been considered central to PKD pathogenesis due to protein localization and common cystic phenotypes in syndromic ciliopathies, but their relevance is questioned in the simple PKDs. ARPKD’s mild phenotype in murine models versus in humans has hampered investigating its pathogenesis. Methods To study the interaction between Pkhd1 and Pkd1 , including dosage effects on the phenotype, we generated digenic mouse and rat models and characterized and compared digenic, monogenic, and wild-type phenotypes. Results The genetic interaction was synergistic in both species, with digenic animals exhibiting phenotypes of rapidly progressive PKD and early lethality resembling classic ARPKD. Genetic interaction between Pkhd1 and Pkd1 depended on dosage in the digenic murine models, with no significant enhancement of the monogenic phenotype until a threshold of reduced expression at the second locus was breached. Pkhd1 loss did not alter expression, maturation, or localization of the ADPKD polycystin proteins, with no interaction detected between the ARPKD FPC protein and polycystins. RNA-seq analysis in the digenic and monogenic mouse models highlighted the ciliary compartment as a common dysregulated target, with enhanced ciliary expression and length changes in the digenic models. Conclusions These data indicate that FPC and the polycystins work independently, with separate disease-causing thresholds; however, a combined protein threshold triggers the synergistic, cystogenic response because of enhanced dysregulation of primary cilia. These insights into pathogenesis highlight possible common therapeutic targets.