Abstract
As a rare autosomal dominant hypopigmentation disease, piebaldism is
characterized by the presence of patchy albinism on the skin, and is
mainly caused by the loss-of-function mutations in c-KIT gene.
Congenital hearing loss is occasionally found as an expanded syndrome of
piebaldism. However, the correlation between c-KIT mutations and
piebaldism with hearing loss has not yet been described. Herein, we
created a mutant strain of miniature pig through the
N-ethyl-N-nitrosourea (ENU)-mediated mutagenesis, which showed severe
piebaldism and congenital profound hearing loss. A genome-wide
association study (GWAS) linked these phenotypes to the
c.2430T>A transition mutation in exon 17 of c-KIT,
resulting in an Asp810Glu substitution in the tyrosine kinase domain.
The Asp810 was localized at the highly conserved DFG motif and the
transition from Asp to Glu would deplete the kinase activity of c-KIT
protein, finally inducing the degeneration of intermediate cells and
hair cells in inner ear. The
c-KITc.2430T>A/+ pig is the first
large animal model with a c-KIT loss-of-function mutation,
showing piebaldism with hereditary hearing loss. It will serve as an
experimental model for exploring the function of c-KIT during biological
processes and the candidate therapies for c-KIT mutations related
diseases.