Who We Are

Wendy Chung, MD, PhD

Clinical and Molecular Geneticist and Physician

Wendy Chung is the Principal Investigator of the GUARDIAN study. She is a clinical and molecular geneticist and the Kennedy Family Professor of Pediatrics and Medicine at Columbia.

Among her many awards, Dr. Chung was the recipient of the NY Academy of Medicine Medal for Distinguished Contributions in Biomedical Science, the Rare Impact Award from the National Organization of Rare Disorders, and the Presidential Award for Outstanding Teaching. She is a member of the National Academy of Medicine and the American Association of Physicians. Dr. Chung has identified over 50 new genetic conditions and has authored over 500 scientific papers. Dr. Chung enjoys the challenges of genetics as a rapidly changing field of medicine and strives to facilitate the integration of genetic medicine into all areas of health care in a medically, scientifically, and ethically sound, accessible, and cost effective manner.

Certified Genetic Counselor

Carrie Koval, MS, CGC

Carrie has been a certified genetic counselor for over 25 years.

Carrie has been a certified genetic counselor for over 25 years. She has worked with families at risk for genetic conditions including childhood and adult-onset conditions. Carrie works with underserved communities and is bilingual in English and Spanish. She has been involved with newborn screening pilot programs for the past 5 years.  She interacts directly with participants of newborn screening studies to provide genetic counseling and facilitate genetic testing as needed.

Research Assistant

Samantha Ratner, BS

Samantha Ratner is a research assistant.

Samantha Ratner is a research assistant. She is an integral member of the research team helping families to make an informed decision about participating in research.

Chief Scientific Officer

Sean Hofherr, PHD, FACMG

Sean Hofherr, PhD, FACMG, is the Chief Scientific Officer, EVP, and CLIA Laboratory Director at GeneDx.

Sean Hofherr, PhD, FACMG, is the Chief Scientific Officer, EVP, and CLIA Laboratory Director at GeneDx. In this role, Dr. Hofherr manages the clinical, scientific, and regulatory areas of the company and he has been on staff since 2017.

Dr. Hofherr has over 10 years of experience in clinical diagnostics with an emphasis on biochemical and molecular testing. Previously, he was the Director of Molecular and Biochemical Genetics at Children’s National Medical Center in Washington, DC where he directed the biochemical genetics lab and built a molecular diagnostics program to support one of the largest pediatric clinical genetics teams. He trained at the Mayo Clinic in Rochester Minnesota. While at Mayo, the biochemical genetics lab performed the state newborn screening for Minnesota through a public private partnership.

Dr. Hofherr is board certified in Clinical Molecular Genetics and Clinical Biochemical Genetics and a Fellow of the American College of Medical Genetics. Dr. Hofherr obtained his PhD from Baylor College of Medicine in Molecular and Human Genetics with a focus and dissertation in the field of Gene Therapy for rare inborn errors of metabolism.

Chief Technology Officer

Kyle Retterer, MS

Kyle Retterer began working for GeneDx in 2010, starting as a Bioinformatics Engineer and quickly moving up to his current position as Senior Vice President and Chief Technology Officer.

Kyle Retterer began working for GeneDx in 2010, starting as a Bioinformatics Engineer and quickly moving up to his current position as Senior Vice President and Chief Technology Officer. Trained in physics and bioinformatics, his career in genomics has focused on building the analytical infrastructure to support the growth and adoption of next-generation sequencing diagnostic testing for germline disorders, including more than 275,000 clinical exomes performed at GeneDx.

Kyle leads a diverse team of scientists and engineers focused on building and scaling genomic analysis, and leveraging massive genomic and phenomic data sets to drive diagnostic efficiency and discovery. His team continues to push the diagnostics field forward by developing platforms and techniques to deliver whole genome sequencing as the next generation standard of care.

Kyle has published more than 50 peer-reviewed articles since 2015, with a special focus on collaborative disease gene discovery and novel analytical approaches to NGS data. He attended the University of Maryland, where he received a Bachelor of Science in Physics and a Master of Science in Biotechnology and Bioinformatics.

Research Scientist

Denise M. Kay, PhD

Dr. Kay is a Research Scientist with the Newborn Screening Program at the New York State Department of Health.

Dr. Kay is a Research Scientist with the Newborn Screening Program at the New York State Department of Health. Her background is in genetics and genetic epidemiology, and her work is focused on addressing challenges in newborn screening, including improving current methods and algorithms, and developing and implementing novel assays for both existing and ‘new’ conditions. A primary focus is on assessment of novel molecular technologies and expanded genetic analysis. The ultimate goal is to translate knowledge gained from these studies into routine public health practice.

Director of Newborn Screening Program

Michele Caggana, Sc.D., FACMG

Dr. Caggana is the Director of the Newborn Screening Program at the New York State Department of Health.

Dr. Caggana is the Director of the Newborn Screening Program at the New York State Department of Health. She is board certified in Clinical Molecular Genetics. She is the Deputy Director for the Division of Genetics and Co-Lead of the Genetic Testing Section for the Clinical Laboratory Evaluation Program. The laboratory has received funding from the Centers for Disease Control and Prevention, the Health Resources and Services Administration, the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the Association of Public Health Laboratories to improve screening and to investigate the addition of new conditions to the panel. Such studies include consented pilots for spinal muscular atrophy and Duchenne muscular dystrophy.