title: [Waardenburg syndrome. A heterogenic disorder with variable penetrance].
abstract: BACKGROUND
  Waardenburg syndrome (WS) is an autosomal dominant disorder characterised by pigmentary anomalies of the skin, hairs, eyes and various defects of other neural crest derived tissues. It accounts for over 2% of congenital hearing impairment. At least four types are recognized on the basis of clinical and genetic criteria.
  
  
  METHODS
  Based on a screening of congenitally hearing impaired children, 12 families with WS type II were detected. Of special interest was the phenotype of these families, in particular the reduced penetrance of hearing impairment within the families.
  
  
  CONCLUSIONS
  In all cases a high variability of the disease phenotype was detected and the penetrance of the clinical traits varied accordingly. Therefore, it is not possible to predict the clinical phenotype even in a single family. Based on these studies, we plan to identify the pathogenetic cause of the disease in order to perform a detailed genotype/phenotype analysis.
authors.affiliation: Hals-Nasen-Ohren-Klinik der Ege-Universität, Izmir, Türkei.
authors.forename: F
authors.initials: F
authors.lastname: Apaydin
authors.forename: M
authors.initials: M
authors.lastname: Bereketoglu
authors.forename: O
authors.initials: O
authors.lastname: Turan
authors.forename: K
authors.initials: K
authors.lastname: Hribar
authors.forename: M M
authors.initials: MM
authors.lastname: Maassen
authors.forename: O
authors.initials: O
authors.lastname: Günhan
authors.forename: H-P
authors.initials: HP
authors.lastname: Zenner
authors.forename: M
authors.initials: M
authors.lastname: Pfister
mesh_terms: D018740:Genetic Heterogeneity; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005820:Genetic Testing; D034381:Hearing Loss / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics*; D015994:Incidence; D019683:Penetrance; D010641:Phenotype; D014421:Turkey / Q000453:epidemiology; D014849:Waardenburg Syndrome / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics*