Frontiers in Genetics (May 2012)

Whole-exome sequencing and an iPSC-derived cardiomyocyte model provides a powerful platform for gene discovery in left ventricular hypertrophy

  • Degui eZhi,
  • Ryan eIrvin,
  • Charles eGu,
  • Alexander eStoddard,
  • Rachel eLorier,
  • Andrea eMatter,
  • D C Rao,
  • Vinodh eSrinivasasainagendra,
  • Hemant K Tiwari,
  • Amy eTurner,
  • Ulrich eBroeckel,
  • Donna K Arnett

DOI
https://doi.org/10.3389/fgene.2012.00092
Journal volume & issue
Vol. 3

Abstract

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Rationale: Left ventricular hypertrophy (LVH) is a heritable predictor of cardiovascular disease, particularly in blacks. Objective: Determine the feasibility of combining evidence from two distinct but complimentary experimental approaches to identify novel genetic predictors of increased LV mass . Methods: Whole exome sequencing (WES) was conducted in 7 African American sibling trios ascertained on high average familial LV mass indexed to height (LVMHT). WES identified 31,426 missense or nonsense mutations (MS/NS) which were examined for association with LVMHT using linear mixed models adjusted for age, sex, body weight, and family relationship. To functionally assess WES findings, human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM) were stimulated to induce hypertrophy; mRNA sequencing was used to determine expression differences associated with hypertrophy onset. Results: After correction for multiple testing, 295 MS/NS variants in 265 genes were associated with LVMHT. We identified 44 of 265 WES genes differentially expressed (P<0.05) in hypertrophied cells. To further prioritize these 44 candidates, 7 supportive statistical and annotation-based criteria were used to evaluate the relevance of these genes. Five genes, HLA-B, HTT, MTSS1, SLC5A12, THBS1, were each supported by 3 criteria. THBS1 encodes an adhesive glycoprotein that promotes matrix preservation in pressure-overload LVH and harbors conserved and predicted damaging variants. Conclusions: Combining evidence from cutting-edge genetic and cellular experiments can enable identification of novel LVH risk loci.

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