Description of Research Expertise

I am a neonatologist with a research interest in the genetic basis of cardiac development and the molecular mechanisms of congenital heart disease. One of my research projects focuses on understanding DiGeorge syndrome, a relatively common syndrome affecting newborns. Patients with DiGeorge syndrome can have a wide variety of problems including deformities of the head and face, speech problems due to improper separation of the oral and nasal cavities, cleft palate, absence or incomplete development of the thymus and parathyroid glands, and problems with the aortic arch and outflow tract of the heart. The cardiac defects associated with the syndrome, often severe, are present in 75 percent of patients and contribute significantly to morbidity.

Most patients with DiGeorge syndrome carry a large genomic deletion of chromosome 22q11. One gene within this commonly deleted region is the transcription factor, TBX1. My colleagues and I identified the molecular mechanism by which a human TBX1 mutation results in DiGeorge syndrome. Additionally, through work with embryonic stem cells, we identified a new Tbx1 interacting protein that is critical for the earliest stages of embryonic development and may be important in understanding the function of Tbx1. Understanding the mechanisms of Tbx1 function will provide insight into both normal and abnormal cardiac development.

A second research project is to identify genes that are critical for differentiating the left sixth aortic arch artery into the ductus arteriosus. Patent ductus arteriosus, a condition in which a child’s ductus arteriosus does not close after birth, is major cause of neonatal morbidity and therapeutic options are limited. A better understanding of what differentiates the left sixth aortic arch artery from the other aortic arch arteries during development will elucidate potential targets for future pharmacologic treatment strategies and has the potential to improve long-term outcomes among extremely low birthweight neonates. Tools used for this project include RNA transcript microarrays and in vivo disease models.