Abstract
Background: Waardenburg syndrome (WS), a common type of syndromic
hearing loss. A large group of patients affected by WS were found no
mutations in the above gene panel, indicating that there are still
potential genes responsible for WS yet to be detected. Methods: In our
previous study, we established a KITD806E/+ pig pedigree with an
autosomal dominant inheritance model. This model presented congenital
bilateral severe sensorineural hearing loss with hypopigmentation, exact
the same as human WS. Results: Histological analysis of the KITD806E/+
cochlea showed nearly normal structures of the organ of Corti, stria
vascularis and spiral neuron ganglions at E85. Scanning electron
microscopy (SEM) exhibited the auditory hair cells began to degenerate
at E100, and totally gone at P1. Transmission electron microscope (TEM)
showed disorganization of stria vascularis (SV) and intermediate cells
in the middle layer of SV had gone. The absence of endocochlear
potentials also demonstrated the dysfunction of stria. Conclusions:
KITD806E/+ mutation interrupted the development of melanocytes in
cochlea, which led to the malformation and dysfunction of SV, resulting
in degeneration of hair cells and finally hearing loss. Therefore, KIT
was highly supposed to be a newly found gene associated with WS.