Inherited hearing impairment is a highly heterogeneous group of disorders with an overall incidence of about 1 in 2000 newborns. Among them, prelingual, severe hearing loss with no other associated clinical feature (non-syndromic) is by far the most frequent. It represents a serious handicap for speech acquisition, and therefore early detection is essential for the application of palliative tre...

Mitochondrial pathology plays an important role in both inherited and acquired hearing loss. Inherited mitochondrial DNA mutations have been implicated in both syndromic and non-syndromic hearing loss, as well as in predisposition to aminoglycoside ototoxicity. Acquired mitochondrial dysfunction in the absence of mitochondrial DNA mutations has also been proposed as playing an important role in...

The MYO7A gene encodes a protein belonging to the unconventional myosin super family. Mutations within MYO7A can lead to either non syndromic hearing loss or to the Usher syndrome type 1B (USH1B). Here, we report the results of genetic analyses performed on Moroccan families with autosomal recessive non syndromic hearing loss that identified two families with compound heterozygous MYO7A mutatio...

Inherited hearing impairment is a highly heterogeneous group of disorders with an overall incidence of about 1 in 2000 newborns. Among them, prelingual, severe hearing loss with no other associated clinical feature (non-syndromic) is by far the most frequent. It represents a serious handicap for speech acquisition, and therefore early detection is essential for the application of palliative tre...

introduction: hearing loss is the most common sensory defect in humans, affecting approximately 1 in 1000 neonates in which genetic factors are involved in more than 50%. connexin 26 or gjb2 gene mutations are responsible for half of autosomal recessive non-syndromic hearing losses. the purpose of this study was to determine the gjb2 mutations frequency in autosomal recessive non-syndromic deaf...

Autosomal recessive non-syndromic hearing loss is the most common form of inherited childhood deafness. Identification of the responsible gene in this type of hearing loss presents difficulties because of marked genetic heterogenicity and limited clinical presentation. A two-year-old girl was referred to our clinic because of congenital hearing loss. Family history showed that her brother and s...

Mitochondrial diseases (MD) are a clinically heterogeneous group of disorders that arise as a result of dysfunction of the mitochondrial respiratory chain. Sensorineural hearing loss (SNHL) is often associated to mitochondrial dysfunctions both in syndromic, nonsyndromic forms. SNHL has been described in association to different mitochondrial multisystemic syndromes, often characterized by an i...

Screening for gene mutations in CDH23, which has many exons, has lagged even though it is likely to be an important cause for hearing loss patients. To assess the importance of CDH23 mutations in non-syndromic hearing loss, two-step screening was applied and clinical characteristics of the patients with CDH23 mutations were examined in this study. As a first screening, we performed Sanger seque...

It is estimated that hereditary hearing loss accounts for 60% of deafness in the developed countries. About 30% of hereditary hearing impairment is syndromic which involves other presenting abnormalities along with deafness. There are more than 400 syndromes which include various degrees of hearing impairment with different phenotypes. (Barlow Stewart et al., 2007; Berrettini et al., 2008). Abn...