Clinical Directors

Elizabeth Chao, M.D.

Chief Medical Officer

Dr. Chao graduated with honors from UCLA with a B.S. in Microbiology and Molecular Genetics and received her M.D. from the University of California, Irvine. She completed her training in Clinical Molecular Genetics at the Children's Hospital of Philadelphia (CHOP) and previously served as Associate Director of the Genetic Diagnostic Lab at the University of Pennsylvania. As a Howard Hughes Scholar at the National Human Genome Research Institute (NHGRI), Dr. Chao specialized in genomic technologies such as the development of array-CGH, and applications to cancer genetics. Currently, Dr. Chao is also on faculty at UC Irvine where her research focuses on novel methods for interpreting DNA variants in genomic data sets.

Sharon Mexal, Ph.D.

Director of Clinical Operations

Dr. Mexal graduated with honors from the University of New Mexico with a B.S. in Biology and with a Ph.D. from the Human Medical Genetics Program at the University of Colorado Medical Campus. Dr. Mexal completed her post-doctoral research at the University of Colorado at Boulder Institute for Behavioral Genetics.  Prior to joining Ambry in 2009, she worked as a senior scientist at Cenomed Biosciences, a start-up pharmaceutical company, where she screened novel compounds for anti-psychotic and anti-emetic drug activity. Dr. Mexal has been active in medical genetics research for over a decade and has published numerous articles on the genetics of schizophrenia and tobacco addiction. 

Sha Tang, Ph.D.

Associate Director of Clinical Genomics

Dr. Tang graduated from Wuhan University with a B.S. in Biochemistry and received her M.S. in Molecular Genetics from Chinese Academy of Sciences. She earned her Ph.D. degree in Genetics, Genomics and Bioinformatics studying mitochondrial genomics in nematodes from University of California, Riverside. Dr. Tang then worked at University of California, Irvine as a postdoctoral scholar sponsored by a two-year Research Fellowship with a focus on elucidating molecular etiology for a number of genetic disorders, including cystinosis and optic atrophy. Prior to joining Ambry, Dr. Tang completed her training in Clinical Molecular Genetics at Baylor College of Medicine where her research focused on molecular genetics and diagnosis of mitochondrial disorders. She is certified in clinical molecular genetics by the American Board of Medical Genetics and currently specializes in diagnostic exome analysis.

Chai-Ling Gau, Ph.D.

Laboratory Director

Dr. Gau is certified in clinical molecular genetics by the American Board of Medical Genetics. She graduated with honors from the University of California, Berkeley with a B.A. in Molecular Cell Biology and obtained her Ph.D. in Microbiology, Immunology, and Molecular Genetics from the University of California, Los Angeles (UCLA). She remained at UCLA for her post-doctoral fellowship studying potential gene therapy vectors for treating arginase deficiency. Dr. Gau completed her training in clinical molecular genetics from Cedars Sinai / UCLA Medical Center prior to joining Ambry.     

Tim Vo, Ph.D.

Laboratory Director

Dr. Vo graduated from the University of California, Irvine with a B.S. in Biological Sciences and received his Ph.D. in Molecular Biology and Genetics from Wayne State University. After completing his post-doctoral in the same department, where his work included identifying and characterizing several novel CNS-specific genes located in the 4p16.3 sub-band, Dr. Vo was a clinical fellow in the Detroit Medical Center’s Molecular Genetics Diagnostic Laboratory. While there, he gained experience starting a CLIA-certified molecular laboratory. Dr. Vo was ABMG board certified in 1999 and became the lab’s technical director. He subsequently took a position as a clinical molecular lab director at what was then USLabs prior to joining Ambry in 2004. Dr. Vo is a Clinical Genetic Molecular Biologist in the state of California and currently holds a COQ in New York state.

Brigette Tippin Davis, Ph.D.

Technical Laboratory Director

Dr. Tippin received a B.S. in biological sciences and a Ph.D. in Molecular Biology from the University of Southern California where she received an NIH-NIA fellowship to research defects in DNA replication and repair mechanisms leading to human disease. She completed her post-doctoral training as an NIH Fellow in Clinical Molecular Genetics at the University of California, Los Angeles (UCLA) / Cedars Sinai Medical Center and is certified by the American Board of Medical Genetics. Prior to joining Ambry, Dr. Tippin was on the faculty at Harbor-UCLA Medical Center in the Division of Medical Genetics where her research focused on the development of novel molecular therapeutics for rare-genetic disorders, including lysosomal storage diseases and inherited forms of colon cancer.

Ruth Baxter, PhD

Assistant Laboratory Director

Dr. Baxter received a first-class honors degree in Physiological Sciences from the University of Newcastle upon Tyne, and a Ph.D. from the Dept. of Biochemistry at the University of Dundee, both in the UK. Following postdoctoral studies at Massachusetts General Hospital in Boston, Dr. Baxter joined Biogen Idec as scientist in the fibrosis research group. After 10 years of research aimed at identifying treatments for scarring diseases and improving wound healing Dr. Baxter completed her medical molecular genetics training fellowship at UCLA. She is certified in molecular genetics by the American Board of Medical Genetics. At Ambry, Dr. Baxter specializes in exome analysis.

Melissa Pronold, PhD

Laboratory Director

Dr. Pronold graduated from the University of Wisconsin-Milwaukee with a B.S. in Biological Sciences. She received her M.S. in Epidemiology from the Medical College of Wisconsin, and her Ph.D. in Molecular Epidemiology from the University of Southern California. Her research in the genetics of Ewing Sarcoma was supported by a USC Pre-Doctoral Clinical and Translational Training Award, and also received a Distinguished Merit Award in 2011. Dr. Pronold completed her ABMG Clinical Molecular Genetics fellowship training at the University of California – San Francisco.

Michael Jarvis, PhD

Laboratory Director

Mike graduated from the University of California, Berkeley with a BS in Bioenergetics and obtained his Ph.D. degree in Chemistry and Biochemistry from UCLA. He completed his clinical molecular genetics training fellowship at Cedars Sinai / UCLA Medical Center before joining the research staffs at Specialty Labs and, later, Focus Diagnostics. Prior to joining Ambry, Mike was employed as a Senior Director in Molecular Genetics at Quest Diagnostics, Nichols Institute. He is certified in clinical molecular genetics by the American Board of Medical Genetics, as a Clinical Genetic Molecular Biologist by the State of California, and holds a COQ from the State of New York.

Nambi Ramalingam, PhD

Laboratory Director

Dr. Ramalingam is from India where he received his BS and MS in Agriculture and Plant Breeding and Genetics respectively.   He earned his Ph.D. degree in Human Biological Chemistry and Genetics from the University of Texas Medical Branch at Galveston, TX.   Before joining Ambry, he completed an ABMG fellowship in Clinical Molecular Genetics at Tulane University School of Medicine in New Orleans, LA.

Wendy Alcaraz, PhD

Laboratory Director

Dr. Alcaraz graduated with honors from the University of California, Davis with a B.S. in Genetics and then worked in a research lab identifying mutations that cause congenital myasthenic syndrome.  She earned her Ph.D. degree in Biomedical Sciences from the University of California, San Diego with a NIH pre-doctoral Ruth L. Kirschstein National Research Service Award to study genetic regulation of neuronal precursor proliferation during cerebellar development.   Dr. Alcaraz completed her training in Clinical Molecular Genetics at Baylor College of Medicine, where she was involved in analysis and reporting of clinical whole exome sequencing, before joining Ambry.

James Song, Ph.D.

Associate Laboratory Technical Director

Dr. Song is certified in clinical cytogenetics and clinical molecular genetics by the American Board of Medical Genetics. He graduated from Xiamen University with a B.S. in Microbiology and received his M.S. in Biophysics from Chinese Academy of Medical Sciences and Peking Union Medical College. He earned his Ph.D. in Biomedical Sciences from Mount Sinai School of Medicine of New York University. Dr. Song received his training in clinical molecular genetics from Tulane University and completed his training in clinical cytogenetics from Cedars Sinai/UCLA Medical Center. Prior to joining Ambry, Dr. Song was an assistant cytogenetics laboratory director at Kaiser Permanente (TPMG) Regional Genetics Laboratory.