Our Physicians



Dr. C. Thomas Caskey is board-certified in Internal Medicine and Clinical Genetics with over 35 years of experience in clinical genetics. He is a member of the National Academy of Sciences, Institute of Medicine (Chair, Board on Health Sciences Policy), Royal Society of Canada, past President: American Society of Human Genetics & Human Genome Organization, and Texas Academy of Medicine, Engineering and Science. Tom held esteemed positions at the Human Genetics and Vaccines Discovery at Merck Research Laboratories, West Point, and served as President of the Merck Genome Research Institute.

Dr. Caskey received numerous academic and industry honors. His genetic research identified genetic basis of more than 40 major inheritable diseases and clarified the understanding of anticipation in triplet repeat diseases, including Fragile X, and myotonic dystrophy. His personal identification patent is the basis of worldwide application for forensic science and he is also a consultant to the FBI in forensic science. Dr. Caskey is currently directing a Precision Medicine program with Young Presidents Organization and is Chief Medical Officer for Human Longevity, Inc. His current research focuses on the application of whole-genome sequence, metabolomics, and advanced imaging toward the objectives of precision medicine, prevention of diseases and implementation of accurate treatment strategies.



David S. Karow, M.D., Ph.D., President and Chief Innovation Officer at Human Longevity, Inc., is an evangelist for impacting longevity and optimizing personal performance. His mission at Human Longevity is to become the leader in whole genome genetic interpretation with whole body imaging and advanced blood work to provide the highest caliber health intelligence available. An innovative leader in MR Imaging and genomic analytics, he reminds clients interested in the experience at the Health Nucleus that they can take actionable steps to improve their health and live not only longer, but healthier longer.



Pamila Brar, MD, is the Medical Director for the Health Nucelus. Dr. Brar is an Internal Medicine physician who has always had a deep love of science and for translating complex ideas into accessible information. She is a graduate of Louisiana State University School of Medicine at New Orleans and the Scripps Clinic Internal Medicine Residency, where she was selected Chief Resident. Pamila served as the past president of the American Academy of Private Physicians from 2015 to 2017. This organization promotes the doctor-patient relationship and the business models that enable it. After fifteen years in practice, she made the shift from general Internal Medicine to Precision Medicine when she joined the team at Human Longevity, Inc. in 2015 as the founding Medical Director of the Health Nucleus. She is currently the Chief Medical Officer of the J. Craig Venter Institute in La Jolla.

Keegan Duchicela, MD


Keegan Duchicela, MD, serves as Health Nucleus Medical Director. Dr. Duchicela received his medical degree from the University of California, San Francisco, School of Medicine. He completed his clinical training in family medicine at the Stanford-O’Connor Family Medicine Residency Program, where he continued as clinical faculty. Prior to joining Human Longevity, Inc., Dr. Duchicela was a medical director at Google’s onsite primary care Wellness Centers. Dr. Duchicela is passionate about preventative medicine and using technology to inform, empower, and guide patients in their journey to better health.

Mona Ezzat-Velinov


Mona Ezzat-Velinov, MD, AFMCP, ABIHM, IFMCP, is a Primary Care doctor with over 20 years of practice. She has a specific passion for Functional Medicine and helping patients find answers to chronic disease. After residency training at the University of Michigan and working in underserved areas around the country, Dr. Ezzat-Velinov moved to Northern California to practice in a community setting. When her own health took a turn for the worse, she began pursuing other areas of healing, which led her to Integrative and Functional Medicine. Through her work with One Medical Group and Crossover Health with Apple and Facebook employees, Dr. Ezzat-Velinov has seen firsthand how preventive care and catching a disease process early is important to helping patients stay healthy. She continues to immerse herself in cutting-edge medical care through a vigorous training program.



Jie Liu, MD, MPH, received her medical degree from the University of California-San Diego. She is board certified in Family Medicine. Dr. Liu is passionate about using integrative medicine modalities to help her patients prevent and manage chronic diseases. Prior to practicing medicine, Dr. Liu worked at the Centers for Disease Control and Prevention and the World Health Organization, and remains a public health advocate. She is an adjunct assistant professor in the School of Public Health at San Diego State University.



Heidi Millard, MD, is a board-certified Family Medicine physician who chose her field to empower people with personalized knowledge about their health so they can live longer and better lives. Her father ran a clinic where Dr. Millard was particularly taken with watching his practice positively influence his patients and community. Dr. Millard holds close the Maya Angelou quote “I’ve learned that people will forget what you said, people will forget what you did, but people will never forget how you made them feel.” She graduated from Loma Linda University School of Medicine.

Robyn Heister


Robyn R. Heister, MD, is a physician on staff at Health Nucleus where she enjoys utilizing genetics and precision medicine to optimize patient health. She is Board-Certified in Emergency Medicine and began practicing in California in 2001. After more than fifteen years in Emergency Medicine, Dr. Heister joined the Health Nucleus team with the intent of bringing a clear clinical voice and up-to-date best-practice guidelines to the organization. Her experience in the emergency room led her to develop a keen interest in early interventions that can reduce the risk of developing debilitating chronic conditions which are an enormous burden on patients, families, and the healthcare system alike. Dr. Heister is a believer in the power of effective communication, and as a practicing emergency medicine physician she helped develop new practice strategies for patient interactions that drove better patient compliance and clinical outcomes. She looks forward to continuing this work at Health Nucleus. Dr. Heister is a graduate of UC Davis School of Medicine after which she completed a 4-year Residency Training program at UC San Diego. She earned a B.A. in Human Biology at Stanford University in 1993. Current research interests include identifying effective early detection methods for cancer and evaluating potential implications of carrier status in inborn errors of metabolism.

EVELYNE BISCHOF, MD, MPH, Associate professor

EVELYNE BISCHOF, MD, MPH, Associate professor

Evelyne Yehudit Bischof (Biskup), MD, MPH and Associate Professor at Shanghai University of Medicine and Health Sciences. Her training includes Harvard Medical School and affiliated hospitals (Mass General, Beth Israel, Brigham’s and Dana Farber) as well as additional training through Columbia University and NY University. She is a specialist in Internal Medicine, Artificial Intelligence (AI) and digital health, with a research focus on oncology, preventative and precision medicine, biogerontology, and geronto-oncology. Dr. Bischof spent a decade practicing medicine, lecturing at medical schools and performing clinical and translational research in New York, Shanghai and Basel, Switzerland. She has extensive experience in scientific research and clinical practice at the following well known and highly reputable institutions: Fudan Cancer Institute and Hospital, Shanghai; Zhongshan Hospital (Fudan University), Renji Hospital (Jiaotong University) and Shanghai East Hospital (Tongji University).

Dr. Bischof has published over 70 peer-reviewed papers and is a frequent speaker at scientific and medical conferences. Known for an interest in preserving longevity, Dr. Bischof is well known for her excellent work in the field of medicine on an international and cross-cultural level, e.g. as a board member of the European Federation of Internal medicine, Swiss Society of Internal Medicine, Women’s Brain Project and more.

Our Genomic Scientists



Ying-Chen (Claire) Hou, Ph.D., serves as a Clinical Genomic Scientist at Human Longevity, Inc. Claire received her B.Sc. (Honors) in Molecular Biology and Biochemistry. She joined the Michael Smith Genome Sciences Center, where she completed her Ph.D. in Genetics at the University of British Columbia. Her Ph.D. works have a significant impact in the fields of cell death and autophagy, resulting in seven publications and platform presentations at prestigious conferences. She continued post-doctoral training at SBP Medical Discovery Institute, focusing on a novel kinase, WNK1/HSN2, associated with hereditary sensory neuropathy type II. Prior to joining Human Longevity, Inc., Claire worked at Pathway Genomics as a Genetics Scientist Research & Development and was instrumental in the expansion of the pharmacogenomics tests.



Hung-Chun (James) Yu, Ph.D., serves as Clinical Genomic Scientist at Human Longevity, Inc. Dr. Yu received his degree from the University of Oklahoma studying genome sequencing and functional genomics. He began his post-doctoral training in Children’s Hospital of Philadelphia focusing on pediatric multiple congenital anomaly disorders. He continued his training in the University of Colorado Anschutz Medical Campus and the Children’s Hospital of Colorado, using next-generation sequencing to diagnose unsolved rare diseases. He discovered several new pathogenic genes and new genetic diseases, including a novel vitamin B12 deficiency disorder he named cblX (cobalamin X), because it only affects male patients who carry a mutated HCHC1 gene in X chromosome.

Emily Smith


Emily Smith, MS, CCG, is a board-certified genetic counselor in the Health Nucleus. She received her master’s degree in Genetic Counseling from Northwestern University. Emily developed a cancer genetic counseling service at a small community hospital before moving to Yale School of Medicine where she worked as part of a multidisciplinary team to provide genetic counseling for people who had cardiac diseases. Throughout Emily’s career helping people understand the complex world of genetics and how they impact a person and their family has been her passion. She continues this work at the Health Nucleus.