Prioritizing disease-related genes and pathways by integrating patient-specific iPSC-derived RNA-seq and whole genome sequencing in hypoplastic left heart syndrome

Background - Hypoplastic left heart syndrome (HLHS) with risk of poor outcome has been linked to MYH6 variants, implicating overlap in genetic etiologies of structural and myopathic heart disease. Methods - Whole genome sequencing (WGS) was performed in 197 probands with HLHS, 43 family members, and 813 controls. Data were filtered for rare, segregating variants in three index families comprised of an HLHS proband and relative(s) with cardiomyopathy. WGS data from cases and controls were compared for rare variant burden across 56 cardiomyopathy genes utilizing a weighted burden test approach, accounting for multiple testing using a Bonferroni correction. Results - A pathogenic MYBPC3 nonsense variant was identified in the first proband who underwent cardiac transplantation for diastolic heart failure, her father with left ventricular non-compaction (LVNC), and two fourth-degree relatives with hypertrophic cardiomyopathy. A likely pathogenic RYR2 missense variant was identified in the second proband, a second-degree relative with aortic dilation, and a fourth-degree relative with dilated cardiomyopathy. A pathogenic RYR2 exon 3 in-frame deletion was identified in the third proband diagnosed with catecholaminergic polymorphic ventricular tachycardia (CPVT) and his father with LVNC and CPVT. To further investigate HLHS-cardiomyopathy gene associations in cases versus controls, rare variant burden testing of 56 genes revealed enrichment in MYH6 ( P =0.000068). Rare, predicted-damaging MYH6 variants were identified in 10% of probands in our cohort-four with familial congenital heart disease, four with compound heterozygosity (three with systolic ventricular dysfunction), and four with MYH6-FLNC synergistic heterozygosity. Conclusions - Whole genome sequencing in multiplex families, proband-parent trios, and case-control cohorts revealed defects in cardiomyopathy-associated genes in patients with HLHS, which may portend impaired functional reserve of the single-ventricle circulation.

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Early outcomes and computational fluid dynamic analyses of chimney reconstruction in the Norwood procedure

Interactive CardioVascular and Thoracic Surgery ◽

10.1093/icvts/ivz040 ◽

2019 ◽

Vol 29 (2) ◽

pp. 252-259 ◽

Cited By ~ 2

Author(s):

Satoshi Asada ◽

Masaaki Yamagishi ◽

Keiichi Itatani ◽

Yoshinobu Maeda ◽

Satoshi Taniguchi ◽

...

Keyword(s):

Aortic Arch ◽

Hypoplastic Left Heart Syndrome ◽

Fluid Dynamic ◽

Norwood Procedure ◽

Patient Specific ◽

Shear Stresses ◽

Left Heart ◽

Hypoplastic Left Heart ◽

Flow Profiles ◽

Left Heart Syndrome

Abstract OBJECTIVES The ideal configuration of a reconstructed aortic arch in the Norwood procedure for hypoplastic left heart syndrome is still a matter of debate. Chimney reconstruction was developed to avoid postoperative complications and turbulent flow in the aortic arch. This study sought to clarify early outcomes of the procedure and verify its haemodynamic advantages using computational fluid dynamics (CFD). METHODS Fourteen consecutive patients with hypoplastic left heart syndrome or a variant who underwent chimney reconstruction in the Norwood procedure between January 2013 and March 2018 were enrolled. Median age and body weight at the time of operation were 2.5 months and 4.1 kg, respectively. Thirteen patients (93.9%) had been palliated with previous bilateral pulmonary artery (PA) banding. In addition, patient-specific CFD models of neoarches based on postoperative computed tomograms from 6 patients were created and the flow profiles analysed. RESULTS Survival rates at 1, 3 and 5 years were 76.6%, 67.3% and 67.3%, respectively. No patient developed left PA compression by neoaorta, neoaortic dilation or neoaortic insufficiency. Only 2 patients (14.3%) required surgical intervention for recoarctation. Fontan completion was performed on 5 patients. On CFD analysis, all reconstructed aortic arches showed low energy loss (9.16–14.4 mW/m2) and low wall shear stresses. CONCLUSIONS Chimney reconstruction was a feasible technique when homografts were not readily available. CFD analyses underscored the fact that this technique produced excellent flow profiles. Larger studies should be conducted to clarify long-term outcomes.

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Patient-Specific Induced Pluripotent Stem Cells Implicate Intrinsic Impaired Contractility in Hypoplastic Left Heart Syndrome

Circulation ◽

10.1161/circulationaha.119.045317 ◽

2020 ◽

Vol 142 (16) ◽

pp. 1605-1608 ◽

Cited By ~ 1

Author(s):

Sharon L. Paige ◽

Francisco X. Galdos ◽

Soah Lee ◽

Elizabeth T. Chin ◽

Sara Ranjbarvaziri ◽

...

Keyword(s):

Stem Cells ◽

Induced Pluripotent Stem Cells ◽

Hypoplastic Left Heart Syndrome ◽

Pluripotent Stem Cells ◽

Patient Specific ◽

Left Heart ◽

Hypoplastic Left Heart ◽

Induced Pluripotent ◽

Left Heart Syndrome

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Patient-specific functional genomics and disease modeling suggest a role for LRP2 in hypoplastic left heart syndrome

10.1101/835439 ◽

2019 ◽

Cited By ~ 1

Author(s):

Jeanne L. Theis ◽

Georg Vogler ◽

Maria A. Missinato ◽

Xing Li ◽

Almudena Martinez-Fernandez ◽

...

Keyword(s):

Congenital Heart Disease ◽

Heart Disease ◽

Hypoplastic Left Heart Syndrome ◽

Congenital Heart ◽

Whole Genome ◽

Left Heart ◽

Heart Model ◽

Hypoplastic Left Heart ◽

Left Heart Syndrome ◽

Human Ipsc

ABSTRACTCongenital heart diseases (CHD), such as hypoplastic left heart syndrome (HLHS), are considered to have complex genetic underpinnings that are poorly understood. Here, an integrated multi-disciplinary approach was applied to identify novel genes and underlying mechanisms associated with HLHS. A family-based strategy was employed that coupled whole genome sequencing (WGS) with RNA sequencing of patient-derived induced pluripotent stem cells (iPSCs) from a sporadic HLHS proband-parent trio to identify, prioritize and functionally evaluate candidate genes in model systems. Consistent with the hypoplastic phenotype, the proband’s iPSCs had reduced proliferation capacity. Filtering WGS for rare de novo, recessive, and loss-of-function variants revealed 10 candidate genes with recessive variants and altered expression compared to the parents’ iPSCs. siRNA/RNAi-mediated knockdown in generic human iPSC-derived cardiac progenitors and in the in vivo Drosophila heart model revealed that LDL receptor related protein LRP2 and apolipoprotein APOB are required for robust hiPSC-derived cardiomyocyte proliferation and normal hear structure and function, possibly involving an oligogenic mechanism via growth-promoting WNT and SHH signaling. LRP2 was further validated as a CHD gene in a zebrafish heart model and rare variant burden testing in an HLHS cohort. Collectively, this cross-functional genetic approach to complex congenital heart disease revealed LRP2 dysfunction as a likely novel genetic driver of HLHS, and hereby established a scalable approach to decipher the oligogenic underpinnings of maladaptive left heart development.One sentence summaryWhole genome sequencing and a multi-model system candidate gene validation - human iPSC-derived cardiomyocytes and Drosophila and zebrafish hearts - identified lipoprotein LRP2 as a new potential driver in congenital heart disease and suggests a deficit in proliferation as a hallmark of hypoplastic left heart syndrome.

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Impact of MYH6 variants in hypoplastic left heart syndrome

Physiological Genomics ◽

10.1152/physiolgenomics.00091.2016 ◽

2016 ◽

Vol 48 (12) ◽

pp. 912-921 ◽

Cited By ~ 25

Author(s):

Aoy Tomita-Mitchell ◽

Karl D. Stamm ◽

Donna K. Mahnke ◽

Min-Su Kim ◽

Pip M. Hidestrand ◽

...

Keyword(s):

Myosin Heavy Chain ◽

Hypoplastic Left Heart Syndrome ◽

Heavy Chain ◽

Patient Specific ◽

Compound Heterozygous ◽

Left Heart ◽

Hypoplastic Left Heart ◽

Cardiomyogenic Differentiation ◽

Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) is a clinically and anatomically severe form of congenital heart disease (CHD). Although prior studies suggest that HLHS has a complex genetic inheritance, its etiology remains largely unknown. The goal of this study was to characterize a risk gene in HLHS and its effect on HLHS etiology and outcome. We performed next-generation sequencing on a multigenerational family with a high prevalence of CHD/HLHS, identifying a rare variant in the α-myosin heavy chain ( MYH6) gene. A case-control study of 190 unrelated HLHS subjects was then performed and compared with the 1000 Genomes Project. Damaging MYH6 variants, including novel, missense, in-frame deletion, premature stop, de novo, and compound heterozygous variants, were significantly enriched in HLHS cases ( P < 1 × 10−5). Clinical outcomes analysis showed reduced transplant-free survival in HLHS subjects with damaging MYH6 variants ( P < 1 × 10−2). Transcriptome and protein expression analyses with cardiac tissue revealed differential expression of cardiac contractility genes, notably upregulation of the β-myosin heavy chain ( MYH7) gene in subjects with MYH6 variants ( P < 1 × 10−3). We subsequently used patient-specific induced pluripotent stem cells (iPSCs) to model HLHS in vitro. Early stages of in vitro cardiomyogenesis in iPSCs derived from two unrelated HLHS families mimicked the increased expression of MYH7 observed in vivo ( P < 1 × 10−2), while revealing defective cardiomyogenic differentiation. Rare, damaging variants in MYH6 are enriched in HLHS, affect molecular expression of contractility genes, and are predictive of poor outcome. These findings indicate that the etiology of MYH6-associated HLHS can be informed using iPSCs and suggest utility in future clinical applications.

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