Dr. Elena Greenfeld: Medical Genomics Research Highlight
Dr. Elena Greenfeld is a laboratory geneticist committed to leveraging the evolving field of genomics to create a comprehensive circle of care for patients. To achieve this, she is currently working to implement clinical low-pass genomic sequencing for prenatal diagnosis, offering a more extensive view into reproductive medicine.
Elena is a co-head of the Division of Diagnostic Medical Genetics at Mount Sinai Hospital, an associate professor with the University of Toronto Department of Laboratory Medicine and Pathobiology, and a featured guest lecturer for the Advanced Human Genetics course in the Medical Genomics program (MedGen). Elena had originally trained as a medical doctor (MD) in Russia before moving to Canada. Here, her journey into laboratory genetics began. Upon arriving in Canada, she trained and worked as a Medical Genetics Technologist before starting a PhD at the University of Toronto, where she researched chronic myelogenous leukemia.
Elena was keen to complete her PhD so that she could complete training with the Canadian College for Medical Geneticists (CCMG), a post-doctoral fellowship that would certify her as a laboratory geneticist in Canada. Impressively, she completed her doctorate in only 2.5 years, seamlessly entering the CCMG Fellowship training with the Hospital for Sick Children (SickKids) focusing on clinical cytogenetics. After completing the 2-year fellowship program, she was hired at Mount Sinai Hospital and has been “absolutely loving it” ever since.
Elena would eventually become dual-certified in molecular genetics as well after completing another fellowship at SickKids through CCMG and the American College of Medical Genetics (ACMG). This additional certification was spurred by the intense technological evolution in genomics over the past 10 years – “the technology changed so much, I had to keep up” she explains.
Elena continuously embraced the ever-changing landscape of laboratory genomics throughout her career to “bring new technologies into clinical practice”, primarily focused on prenatal diagnosis. In 2009, Mount Sinai became the first diagnostic lab in Canada to utilize microarrays for pre-implantation genetic diagnosis for embryos. Later, it would become the first to implement microarrays for the detection of fetal chromosomal changes in pregnancy and prenatal diagnoses.
Although these accomplishments remain a point of pride, microarray technology is aging and is now over 15 years old. As such, Elena has now turned to more comprehensive methods, particularly genome sequencing, postulating that it is “likely in the next 5 to 10 years to replace all tests with one, which will be whole genome sequencing.” As such, Elena’s newest project is working to implement Low-pass Whole Genome Sequencing (LP-WGS) for prenatal diagnosis at Mount Sinai Hospital.
Low pass refers to the read depth of sequencing, or how many times a nucleotide can be read during sequencing (check out this video for more information on read depth). For traditional diagnostic WGS, the ideal read depth is around 30x – each nucleotide being sequenced 30 times. However, “low pass means that the [read] depth of the sequencing is lower than what this was currently used for clinical diagnosis… each nucleotide is sequenced 10 times”, Elena explains.
This method enables the detection of copy number variations (CNVs) similar to existing microarrays, while potentially enhancing diagnostic yield by identifying additional abnormalities beyond copy number changes. This increased power can also help to reduce overall diagnostic costs and turnaround time if utilized as a first-tier test. Specifically, Elena mentions that it can reduce the number of individuals needing more expensive deep sequencing analysis upon getting an uninformative microarray. This can further allow for earlier treatments and interventions, which can have huge impacts on mother and child health outcomes.
“What truly brings me satisfaction is the chance to significantly influence patient care, coupled with the knowledge that the testing we provide at Mount Sinai ensures a comprehensive circle of care for the patient.”Dr. Elena Greenfeld
Elena and her team are on track to implement LP-WGS early this year (2024), but the work doesn’t end there. She explains that her long-term goal is to “introduce deep genome sequencing to prenatal diagnosis” as a first-tier standard of care. As genomic testing capabilities evolve, it opens up the potential for in utero testing, diagnosis, and treatment, resulting in healthy newborns and favourable outcomes. Since current methods only lead to diagnoses in 40% of cases, WGS fills in that testing and diagnosis gap, “contributing to personalized medicine”.
Elena's passion for clinical genetics centers on patient care, and her dedication to integrating new genomic technologies plays a vital role in guaranteeing that patients receive the comprehensive healthcare they deserve. Moreover, she has an endless fascination accompanying her expertise, making her a very welcomed guest lecturer and a widely sought-after practicum supervisor. We are grateful to have her as part of our program and always excited to see her work evolve.
