UROP Fellowship: Biomedical and Life Sciences
Research Mentor(s): Elaine Ritter, PhD
Research Mentor Institution/Department: Michigan Medicine, Department of Pediatrics
Presentation Date: Wednesday, August 4th
Session: Session 1 (3pm-3:50pm EDT)
Breakout Room: Room 2
CHARGE Syndrome is a multiple malformation condition that is characterized by congenital abnormalities including coloboma of the eye, heart defects, atresia choanae, retardation of growth, genital abnormalities, and ear abnormalities. A hallmark feature of CHARGE is ear abnormalities which manifest as conductive and sensorineural hearing loss and balance disorders. The primary cause of CHARGE is pathogenic variants in the gene CHD7 (Chromodomain Helicase DNA binding protein 7), which encodes an ATP-dependent chromatin remodeling protein. Loss of Chd7 disrupts development of the neural crest, a transient migratory cell population that gives rise to a variety of cell types including sensory neurons and myelinating Schwann cells of the inner ear. Given that proper myelination is essential for peripheral auditory system function, we hypothesized that pathogenic variants in CHD7 disrupt sensory neurons and myelinating Schwann cells in the cochlear spiral ganglion. To test this, we measured the number and density of sensory neurons and myelinating Schwann cells in Chd7Gt/+ mice, which are a model of human CHARGE Syndrome. We found no significant differences in the number or density of neurons or myelinating Schwann cells in the spiral ganglion of Chd7Gt/+ compared to wild type mice. These results suggest that hearing loss in CHARGE may not be caused by improper development of neurons and myelinating Schwann cells in the spiral ganglion. Further studies are necessary to determine the etiology of hearing loss caused by CHARGE.