Characterization of Sensorineural Hearing Loss in Neurofibromatosis Type 2
Neurofibromatosis
Type 2 (NF2) is a rare genetic condition where non-cancerous Schwann cell
tumors develop along the balance portion of the hearing and balance nerve in
both inner ears. Through unknown mechanisms, this also affects the hearing
portion of the ear and ultimately leads to deafness in both ears in children
with NF2. The hearing loss caused by NF2 is a big challenge for children and
young adults, as it isolates them from their environment and affects their
overall development. The hearing loss is not dependent on the tumor itself,
patients with small tumors can be deaf and patients with large tumors can have
normal hearing. To this day, we do not know why and when this hearing loss
happens in children with NF2, or why it can get worse even if the tumors aren’t
growing.
Our
new research in mice with NF2 suggests that Schwann cells in the hearing
portion of the ear are not functioning properly long before these animals form
tumors on the balance nerve. A lack of and abnormal nerve isolation appear to
be the underlying reason for worsening hearing loss over time.
To
understand the hearing loss in children with NF2 better, we will study inner
ears from these animals at different ages to see how the Schwann cell coverings
change around the hearing nerve and how they may get affected by a type of
immune cell called macrophages.
Overall,
this research aims to shed light on why there is hearing loss in patients with
NF2 and may help us find new ways to prevent or treat this hearing loss in the
future.