title: Hearing loss in Waardenburg syndrome: a systematic review.
abstract: Waardenburg syndrome (WS) is a rare genetic disorder characterized by hearing loss (HL) and pigment disturbances of hair, skin and iris. Classifications exist based on phenotype and genotype. The auditory phenotype is inconsistently reported among the different Waardenburg types and causal genes, urging the need for an up-to-date literature overview on this particular topic. We performed a systematic review in search for articles describing auditory features in WS patients along with the associated genotype. Prevalences of HL were calculated and correlated with the different types and genes of WS. Seventy-three articles were included, describing 417 individual patients. HL was found in 71.0% and was predominantly bilateral and sensorineural. Prevalence of HL among the different clinical types significantly differed (WS1: 52.3%, WS2: 91.6%, WS3: 57.1%, WS4: 83.5%). Mutations in SOX10 (96.5%), MITF (89.6%) and SNAI2 (100%) are more frequently associated with hearing impairment than other mutations. Of interest, the distinct disease-causing genes are able to better predict the auditory phenotype compared with different clinical types of WS. Consequently, it is important to confirm the clinical diagnosis of WS with molecular analysis in order to optimally inform patients about the risk of HL.
authors.affiliation: Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, People's Republic of China.
authors.forename: J
authors.initials: J
authors.lastname: Song
authors.affiliation: Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, People's Republic of China.
authors.forename: Y
authors.initials: Y
authors.lastname: Feng
authors.affiliation: Department of Otorhinolaryngology, Ghent University/Ghent University Hospital, Ghent, Belgium.
authors.forename: F R
authors.initials: FR
authors.lastname: Acke
authors.affiliation: Department of Medical Genetics, Ghent University/Ghent University Hospital, Ghent, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Coucke
authors.affiliation: Department of Medical Genetics, Ghent University/Ghent University Hospital, Ghent, Belgium.|Department for Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Vleminckx
authors.affiliation: Department of Otorhinolaryngology, Ghent University/Ghent University Hospital, Ghent, Belgium.
authors.forename: I J
authors.initials: IJ
authors.lastname: Dhooge
keywords: Waardenburg syndrome; genotype; hearing loss; inner ear malformation; phenotype