Wendy K. Chung, M.D., Ph.D.
Assistant Professor of Pediatrics 

Dr. Wendy Chung is a human geneticist whose current research activities include efforts to identify genes and their relevant allelic variants related to the development of congenital diaphragmatic hernia, congenital cardiac malformations including heterotaxy, hypoplastic left heart syndrome, cardiac septal defects, cardiomyopathies, and congenital and acquired long QT syndromes.

As a clinical geneticist, I treat children and adults with many types of genetic disorders.  Increasingly, we are identifying the underlying molecular basis of disease, and as a result making connections between disparate diseases that were initially thought to be unrelated.  We have discovered that defects in channels (channelopathies), or openings within cells, lead to abnormal flow of salts in and out of cells.  Genetic channelopathies cause diseases including diabetes, arrhythmias or electrical disturbances of the heart, and some types of seizures including Dravet syndrome.  Dravet syndrome is due to a genetic defect in a sodium channel gene called SCN1A.  We are beginning to develop therapies for some channelopathies taking advantage of what we know about how these channels work.  For example in certain arrhythmias associated with a high risk of sudden death, the molecular defect is a sodium channel SCN5A that remains open too long.  We can now use available medications that act to close or block the sodium channel.  In a similar way, there is a rare form of diabetes caused a genetic mutation in a potassium channel that remain open too long.  This rare form of diabetes is also associated with seizures and muscle weakness.  We can now use an available medication called a sulfonylurea that acts to block those potassium channels and treat the diabetes without the need for insulin injections.  Importantly, not only does the sulfonylurea treat the diabetes, but it also treats the seizures and muscle weakness.  Although the gene for Dravet syndrome is different than the genes for arrhythmias or diabetes, the hope is that drugs can be identified that will also be used to treat seizures due to mutations in other channelopathies in the brain.

Finding effective medications however can be challenging.  Even among patients with the same type of channelopathy, there may be differences in how they respond to medications that we do not yet understand.  We have wondered if the difference might be due to genetic differences in others genes besides the primary channel gene.  We are beginning to address this question with a new and exciting method called induced pluripotent stem cells.  We take a small piece of skin from the patient and trick the cells into becoming pancreas cells, heart cells or even neurons.  These cells are genetically identical to the person from whom they came and allow us to test the effect of medications on the patient in a test tube rather than having to use trial and error methods of trying medications in the child.  I hope that these methods will be useful not only to test medications that are already FDA approved and on the market but also to screen through libraries of chemicals that could potentially be used in the future to develop better anti-epileptic medications.  The treatment for seizures will however not be easy.  There is a fine line to walk between controlling seizures effectively and keeping a child alert and functional in their day to day activities.  Although the solutions may not come easily or quickly, there are more and more available strategies to develop better treatments for the future.