Waardenburg syndrome type I: Dental phenotypes and genetic analysis of an extended family

BACKGROUND: The aim of this study was to describe the pattern of inheritance and the clinical features in a large family with Waardenburg syndrome type I (WS1), detailing the dental abnormalities and screening for PAX3 mutations. MATERIAL AND METHODS: To characterize the pattern of inheritance and clinical features, 29 family members were evaluated by dermatologic, ophthalmologic, otorhinolaryngologic and orofacial examination. Molecular analysis of the PAX3 gene was performed. RESULTS: The pedigree of the family,including the last four generations, was constructed and revealed non-consanguineous marriages. Out of 29 descendants, 16 family members showed features of WS1, with 9 members showing two major criteria indicative of WS1. Five patients showed white forelock and iris hypopigmentation, and four showed dystopia canthorum and iris hypopigmentation. Two patients had hearing loss. Dental abnormalities were identified in three family members, including dental agenesis, conical teeth and taurodontism. Sequencing analysis failed to identify mutations in the PAX3 gene. CONCLUSIONS: These results confirm that WS1 was transmitted in this family in an autosomal dominant pattern with variable expressivity and high penetrance. The presence of dental manifestations, especially tooth agenesis and conical teeth which resulted in considerable aesthetic impact on affected individuals was a major clinical feature. Clinical relevance: This article reveals the presence of well-defined dental changes associated with WS1 and tries to establish a possible association between these two entities showing a new spectrum of WS1. Key words:Waardenburg syndrome, hearing loss, oral manifestations, mutation.