Who We Are, Where We've Been and What We've Accomplished
Ray E. Hershberger, MD
Dr. Hershberger is a Professor of Medicine, a heart failure and transplant cardiologist, and a clinical and laboratory scientist who directs the DCM (formerly, FDC) Research Project. He and his group continue their research efforts to discover and understand the genetics and genomics of human dilated cardiomyopathy and translate new knowledge into the practice of cardiovascular medicine. In his current position at The Ohio State University College of Medicine since 2012, he directs the Division of Human Genetics in the Department of Internal Medicine and is jointly appointed in the Cardiovascular Division. He devotes his outpatient clinical effort to cardiovascular genetics and also serves with the in-patient heart failure and cardiac transplantation service. Dr. Hershberger received his cardiovascular training at the University of Utah in Salt Lake City from 1985 – 1990, which included a heart failure and cardiac transplantation fellowship and a three year laboratory-based research fellowship. In 1990 he joined the faculty of the Division of Cardiology at the Oregon Health & Science University (OHSU) in Portland, Oregon, as a heart failure and transplant cardiologist. Dr Hershberger started the Familial Dilated Cardiomyopathy (FDC) Research Project in 1993 while at OHSU. He also directed the OHSU Heart Failure and Transplant Cardiology programs from 1993-2007. In 2007 Dr. Hershberger joined the Miller School of Medicine at the University of Miami in Miami, Florida, where he served as Associate Chief of the Division of Cardiology, Director of the Advanced Heart Failure Therapies Programs, and Director of Translational Cardiovascular Genetic Medicine. You may contact Dr. Hershberger via email at Ray.Hershberger@osumc.edu, his office phone number at 614-688-1388, or his direct line at 614-688-1305.
CLINICAL SCIENCE PERSONNEL
Ana Morales, MS, LGC
Licensed Genetic Counselor
Ana Morales received her undergraduate degree in Biology at the University of Puerto Rico (Rio Piedras). In 2001, she obtained her graduate degree in genetic counseling from Brandeis University, Waltham, MA. Ana provides scientific direction and assistance for cardiovascular research studies in cardiovascular genomics, including participation in the development of original research proposals, writing manuscripts, and presenting at conferences. She also directs clinical research personnel, enrolls new families, addresses genetic counseling issues, maintains the project’s database and publishes the DCM Beat Newsletter. Ana also assists with grant reports and submissions, interprets research results and directs return of research DNA test results using CLIA compliant protocols. Within the DCM Study, her focused area of work is peripartum cardiomyopathy (PPCM) and the related clinical genetic counseling aspects of this condition. Her work has resulted in publications addressing clinical genetics and psychosocial issues that are relevant to PPCM and DCM. In 2012, she relocated to The Ohio State University, where she continues to work on the DCM Research Project.
How the Dilated Cardiomyopathy Research Project started and has progressed
Why is our group studying dilated cardiomyopathy (DCM)? Dr. Hershberger chose this area of research following the 1992 report that 20% of cases of DCM of unknown cause (idiopathic DCM, IDC) could be shown to be familial with clinical screening of family members. This evidence indicated a genetic cause for DCM. Since then, our goal has been to identify the genetic causes of DCM in order to better understand how DCM progresses, and to eventually devise new therapies for cardiomyopathy and heart failure. It is our sincere hope that the information gained from studying individuals and families with DCM will lead to prevention, earlier diagnosis or better treatments for DCM.
Ray Hershberger, MD started the Familial Dilated Cardiomyopathy (FDC) Research Project in 1993 at Oregon Health & Science University. At that time none of the genetic basis of DCM had been discovered. The goals of the study were to discover the genes and their variants causing DCM and to translate these discoveries into the practice of cardiovascular medicine. At that time, our research was focused on large families with multiple affected individuals, which are ideal for linkage and gene mapping studies.
Since 1993, Dr. Hershberger has recruited all personnel and has directed all aspects of the research effort. Our research team is composed of clinicians and scientists in cardiology and genetics. In September 1995 Mike Litt, PhD brought his expertise in linkage analysis and gene mapping to the FDC research project. A small grant in 1996 supported genotyping that was used for preliminary data for the first NIH submission. Funding from the National Heart, Lung and Blood Institute (NHLBI grant number HL 58626) of the National Institutes of Health (NIH) was activated in May 1998. Shortly following, Petra Jakobs, PhD, joined the laboratory effort. In late 1998, Emily Burkett (Hanson), MS, CGC (certified genetic counselor) joined the project to assist with rapid expansion of FDC large and small families.
NIH research funding, first received in 1998 and renewed in 2002 and 2008, has provided the core support for all of our research activities. In 2000 we obtained a single capillary-based genotyping instrument to facilitate genotyping activities. In 2001, Jessica Kushner, MS, CGC joined the group. Around this time, the project expanded to accept participants with non-familial DCM, and by 2005, Dr. Hershberger and his team had enrolled more than 300 families. Duanxiang Li, MD, MS, a laboratory-based cardiovascular scientist from Baylor University, joined the research group on August 1, 2002. Sharie Parks, PhD, a laboratory-based geneticist joined the group on September 1, 2002. Susan Ludwigsen, MA joined the group as a Research Associate to assist with bioinformatics in January 2002. In 2003 we acquired a 16 capillary-based instrument to expedite genotyping and gene sequencing in our laboratory. With this investment, our families underwent research genetic testing for single genes. NIH support through the NHLBI-funded Resequencing and Genotyping Service enabled sequencing of our cohort for small gene panels.
In March 2007, the project moved to the University of Miami (UM). Dr. Li accompanied Dr. Hershberger to Miami and continued the laboratory work. Two genetic counselors, Jason Cowan, MS, and Ana Morales, MS, LGC and laboratory technician Jorge Gonzalez were recruited to the program. In 2008, Jill Siegfried, RN, MS, CGC, was recruited into the program as a genetic counselor. Laura Hudson, MA, MPH, CCRC (certified clinical research coordinator) was hired as a regulatory specialist in 2008. In 2009, Nadine Norton, PhD, joined the group as a laboratory scientist. With his newly formed team, Dr. Hershberger continued his research on selected genes, which eventually expanded to exome sequencing and zebrafish functional studies. By then, over 400 families had enrolled; however, it became clear that a much larger number of families would be required for progress. Based on this idea, in 2009 Dr. Hershberger began developing the DCM Consortium. By 2010, Dr. Hershberger had recruited 5 institutions external to UM. A NIH proposal from the Consortium, focused on gene discovery leveraging exome sequencing, was nearly funded in 2011.
In 2012, Dr. Hershberger was recruited by The Ohio State University (OSU)/Wexner Medical Center in Columbus, Ohio, as Director of the Division of Human Genetics within the Department of Medicine. Drs. Hershberger and Li and Ana Morales, MS, CGC, moved the FDC Research Project to OSU. In April 2013, the Familial Dilated Cardiomyopathy (FDC) Research Project became the Dilated Cardiomyopathy (DCM) Research Project to better communicate that we welcome individuals with DCM with or without a family history. Dr. Hershberger’s group has grown at OSU, with the recruitment of Dan Kinnamon, PhD, biostatistician, Debra Wheeler, BS, laboratory manager, and Jennifer Rinehart, BS, clinical research coordinator.
As of 2015, more than 700 families have enrolled in our research, and over 400 participants have been exome sequenced. At OSU, Dr. Hershberger expanded his zebrafish functional studies in collaboration with Dr. Christine Beatty.
A major emphasis of Dr. Hershberger’s work at OSU has been the development and funding of the DCM Consortium. Research involving cardiovascular screening, research genetic testing with return of results, as well as a randomized trial of communication among relatives regarding genetic risk is now done in families of European, African, and Hispanic ancestry.
Since 1993 numerous other nurses and clinical and laboratory researchers have assisted with this Project at OHSU, UM and OSU, and many have participated as coauthors in our publications. We also recognize the hundreds of families who have participated in our research, and dozens of physicians, nurses and genetic counselors who have referred patients and families to us. Thank you!
What We've Accomplished
Please see our Publications page for a full citation of our publications
BAG3. In 2011, we identified rare variants in BAG3 (BCL2-associated athanogene 3) as causative of DCM by using comprehensive genomic approaches (Norton et al., Am J of Human Genetics 2011; 88:273-282). Applying both genome-wide copy number and whole-exome sequencing analysis in a large FDC pedigree with autosomal dominant transmission, we identified 428 single point variants, 51 insertion deletions and 440 copy number variants > 1 kb. Of these, a 8733 bp deletion in BAG3 was found in seven affected family members. The deletion was absent in 355 controls. Knockdown of bag3 in a zebrafish model recapitulated DCM and heart failure. Sequencing of coding regions in 311 additional unrelated probands identified one frameshift, two nonsense, and four missense rare variants absent in 355 control DNAs, four of which were familial and segregated with disease.
PSEN1 and PSEN2. In 2005 we undertook a candidate gene study by sequencing PSEN1 and PSEN2 in DNA samples from 315 DCM probands (Li et al, AM J of Human Genetics 2006;1030-39). A novel PSEN1 mutation was found in 1 FDC family, and a single PSEN2 mutation was found in 2 unrelated FDC families. Calcium flux studies in cultured fibroblasts from family members harboring these mutations were consistent with aberrant presenilin function. Combined mutation frequencies in the cohort were 1%.
SELECTED OTHER GENE SEQUENCING STUDIES
Exome sequencing in large FDC families. Our initial focus in the 1990s was large FDC families (meaning several affected subjects in one extended family), extremely helpful at linkage analysis and gene mapping for novel gene discovery. Recent developments in sequencing technology have now made it possible to sequence all genes that encode proteins simultaneously, termed exome sequencing. We used both linkage analysis and exome sequencing of 48 individuals with DCM from 17 families to analyze TTN truncating mutations (Norton, et al, Circ Cardiovasc Genetics 2013;6:144-53). We identified six TTN truncating variants in 7 families. By linkage analysis the TTN region fell under the second highest genome-wide multipoint linkage peak (MLOD 1.59). Two additional novel truncating TTN variants did not segregate with DCM. We also found that while the average number of missense variants per individual was ~23, the average number of TTN truncating variants was 0.014 per individual. These data suggest that TTN truncating variants contribute to DCM cause. However, the two families with non-segregating TTN mutations illustrate the challenge of determining the role of TTN in DCM.
BAG3. In 2011, we conducted exome sequencing in 68 individuals from 22 of our largest FDC families. We discovered BAG3, noted above, and others still in progress. We also developed an exome variant calling pipeline and conducted zebrafish-based functional studies.
LMNA. In 2001 we sequenced LMNA our larger, linkage families (FDC-1 to FDC-16) to exclude lamin A/C mutations as a cause for FDC and identified three families with novel LMNA mutations (Jakobs et al., J Cardiac Failure 2001;7:249-256; Hershberger et al., Am Heart J 2002; 144:1081-6). We also sequenced LMNA in our 300+ cohort of DCM probands and identified 18 mutations in 19 probands (including the 3 previously reported) for an overall mutation frequency of 5.9%. (Parks SB et al., Am Heart J 2008;156:161-9).).
Resequencing 11 DCM genes. With an RS&G Service award, 11 DCM genes were resequenced in 312 DNAs from our cohort at OHSU in two studies. The genes included beta-myosin heavy chain (MYH7), cardiac troponin T (TNNT2), the cardiac sodium channel (SCN5A), titin-cap or telethonin (TCAP), LIM binding domain 3 (LDB3), and muscle LIM protein (CSRP3) in the first study. Myosin-binding protein C (MYBPC3), alpha-myosin heavy chain (MYH6), tropomyosin (TPM1), cardiac troponin C (TNNC1), and cardiac troponin I (TNNI3) were sequenced in the second study. Variants were classified as likely or possibly disease-causing in approximately 10%. Notably, the frequencies of mutations in patients categorized either with FDC or apparently sporadic IDC were similar. Overall, mutations in these 11 genes were identified in approximately 27% of DCM probands.
RBM20. In 2010, 312 DCM probands were evaluated for nucleotide alterations in exons 6 through 9 of RBM20. We found six unique RBM20 rare variants in 1.9%. Four mutations, two of which were novel (R634W and R636C) and two previously identified (R634Q and R636H), were identified in a hotspot in exon 6. Two other novel variants (V535I in exon 6 and R716Q in exon 9) were outside of this hotspot. We also observed that RBM20 mutations are associated with advanced disease.
‘Small’ FDC Families. We actively recruit smaller FDC families (defined as having at least 2 members with DCM). For these families, we have obtained medical documentation of disease and collected genetic material. With exome sequencing these small FDC families now also play an invaluable role as novel FDC genes are discovered and described.
Apparently Sporadic Families. We actively recruit families in which only one individual is known to have IDC, as evidence shows that genetics can play a role in disease causation even in the absence of a family history. Because DCM can be asymptomatic, participation of parents, children and siblings who have undergone screening is particularly essential in sporadic families to understanding the genetics of DCM.
Clinical data. The clinical characteristics of some of our initial very large FDC kindreds have been published (Crispell et al., J Am Coll Cardiol 1999; 34:837-847<). A follow-up account of one of these families substantiated the value of periodic rescreening of first-degree relatives of subjects with FDC (Crispell et al., J Am Coll Cardiol 2002; 39:1503-1507). We have also characterized numerous additional smaller to intermediate size FDC families (Kushner et al., J Cardiac Failure 2006;12:422-29), and have accumulated a great deal of experience with the screening evaluation process related to this work. We also notify participants when relevant research results are available and provide assistance during the confirmatory testing process (Siegfried et al., J Genetic Counseling 2013; 22:164-74).
Offsite Screening Trips. We have completed greater than 25 distant screening trips, including locations in Oregon, Washington, Arizona, California, Illinois, Iowa, Indiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, Oklahoma and Tennessee. Our heartfelt thanks to the many gracious and wonderful physicians, nurses and office managers who have given us permission and assisted us in the use of their offices (exam rooms, echo and ECG equipment, and many other smaller items) in these weekend screening trips, and to the many fine echocardiographic technicians who have assisted with echo screening of these families.