Master Class

Use of genetic testing for congenital heart defect management


 

The average student in America learns that genes form the building blocks of what makes us human by the time they receive their high school diploma. Indeed, the completion of the Human Genome Project in 2003 paved the way for our genetic makeup, much like our medical history, to become a routine part of our health care. For example, our faculty at the University of Maryland School of Medicine discovered an important gene – CYP2C19 – which is involved in the metabolism of the antiplatelet medicine clopidogrel (Plavix). Although most people have this gene, some don’t. Therefore, when we manage a patient with coronary disease, we use a genetic screen to determine whether that patient has CYP2C19 and then modify therapy based on these results.

Dr. E. Albert Reece, vice president for medical affairs at the University of Maryland, Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor and dean of the school of medicine.

Dr. E. Albert Reece

Our genes also have become commodities – from companies willing to analyze our genes to determine our racial and ethnic ancestry or propensity for certain diseases to those that can sequence the family dog’s genes.

Advances in genomics similarly have impacted ob.gyn. practice. Because of rapidly evolving gene analysis tools, we can now, for example, noninvasively test a developing fetus’s risk for chromosomal abnormalities and determine a baby’s sex by merely examining fetal DNA in a pregnant woman’s bloodstream. Although not diagnostic, these gene-based prenatal screening tests have reduced the need for unnecessary, costly, and highly invasive procedures for many of our patients.

Importantly, our recognition that certain genes can confer a higher risk of disease has meant that performing a prenatal genetic evaluation can greatly inform the mother and her care team about potential problems her baby may have that may require additional management. For babies who have congenital heart defects, a genetic evaluation performed in addition to sonographic examination can provide ob.gyns. with crucial details to enhance pregnancy management and postnatal care decisions.

The importance of genetic testing and analysis in the detection, treatment, and prevention of congenital heart defects is the topic of part two of this two-part Master Class series authored by Shifa Turan, MD, associate professor of obstetrics, gynecology, and reproductive sciences at the University of Maryland School of Medicine and director of the Fetal Heart Program at the University of Maryland Medical Center. By using a combination of three- and four-dimensional ultrasound with gene assays, Dr. Turan and her colleagues can greatly enhance and personalize the care they deliver to their patients.

Dr. Reece, who specializes in maternal-fetal medicine, is executive vice president for medical affairs at the University of Maryland School of Medicine, as well as the John Z. and Akiko K. Bowers Distinguished Professor and dean of the school of medicine. He is the medical editor of this column. He said he had no relevant financial disclosures. Contact him at obnews@mdedge.com.

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