HNF4A and deafness: Based on the fact that the R63 residue is in the DNA-binding domain and directly contacts the DNA response element, we speculated that the heterozygous p.R63W mutation in our patient reduced DNA binding activity and altered expression of some target genes related to otic capsule development or associated hearing loss; on the other hand, according to Stamatiou and Stankovic [10], HNF4A appeared to be a central player in the network and was an attractive gene for hearing loss based on network analysis of human deafness.