Genetic hearing impairment : a clinical study of various dominant inherited types

Abstract

In this thesis a presentation is given of different patterns of inheritance, present in the cochlea or in the auditory chain of ossicles. Presentation and diagnosis of hereditary hearing loss is reviewed. A rare pattern of inheritance is the so called mitochondrial or maternal inheritance. In this rare form of deafness the deafness is transmitted from a mother to all her children and stops in male to male transmission. This means that affected men have normal children. Besides the hearing loss a progressive neurological diseases occurs later in life and is characterized by muscle fatigue and coordination problems. In the third chapter some Dutch families with autosomal dominant patterns of inheritance of non-syndromal deafness are described. Responsible DNA defects are today identified in all six Dutch families.The thesis ends with the description of four rare syndromes with anomalies in the ossicular chain. All children were successfully operated.