The article discusses the priorities of cochlear implantation (CI) in the RS (Ya). The results of the CI in Yakutsk to 11 children are presented. All patients in the preoperative period underwent general clinical examination, examination of ENT organs, earmicroscopy, acoustic impedance measurement, a study of otoacoustic emission and short-latency auditory evoked potentials research. A computed tomography of temporal bones with a 2 mm cut thickness was also performed. All patients were examined by a speech therapist and the faculty for the purpose of determining the level of general development, auditory and speech perception and development of speech. All patients were operated using Neurelec implants (France). The need for further introduction of high-tech care for children to improve the quality of life was noted.

The results of computer tomography (CT) and magnetic resonance imaging (MRI) of a rare case the analysis of the images is performed and a detailed description of changes on CT and MRI studies is given. This case of aplasia is characterized by symmetrical agenesia of the of bilateral aplasia of cochlea and semicircular canals of the inner ear are presented. In this article cochlea and semicircular canals, and bilateral abnormality of the facial nerve canal, and abnormality of the internal auditory foramen on both sides, as well as unilateral agenesis of the abducent nerve and bilateral agenesis vestibulocochlear nerve. Results of the study indicate a high informative method of CT in the diagnosis of the inner ear abnormalities, as well as the possibility of using MRI in visualizing the cerebellopontine angle for the entire description of its clinical picture.

In this article results of the audiological examination testifying to auditory threshold variability at deaf patients with splice site c.-23+1G>A mutation in GJB2 gene in homozygous state are presented. According to this study this GJB2-genotype is characterized by (horizontal) flat orsloping audioprofile. There are recommendations for applying the results obtained in practice.

This study presents data on the carrier frequency of IVS1+1G>A mutation in GJB2 gene, leading to autosomal recessive form of deafness among various ethno-geographical groups of Yakut population and in a random sample of the Yakuts. 350 DNA samples of hearing individuals from various ethno-geographical groups of Yakut population: Central (n=60), Vilyui (n=60), Northern (n=60) and random samples of Yakuts (n=170) were obtained from the DNA Bank of the Department of Molecular Genetics of Yakut Research Center of Complex Medical Problems of RAMS (Yakutsk, Russian Federation). The average carrier frequency of IVS1+1G>A mutation in Yakut population (n=350) detected was - 10.3%. Extremely carrier frequency of the splice site IVS1+1G>A mutation in GJB2 gene in the Yakut population is comparable to the carrier frequency of the sickle-cell anemia in Africa, which may indicate a possible selective advantage of carriers of this IVS1+1G>A mutation in a subarctic climate.

In this study we registered a large cohort of Yakut patients homozygous for the IVS1+1G>A mutation ( 70 unrelated deaf subjects in total). The extremely high carrier frequency of the IVS1+1G>A mutation (11.7%) from six investigated populations has been found in Yakut population. Reconstruction of 140 haplotypes with IVS1+1G>A mutation demonstrates the common origin of all mutant chromosomes found in Yakuts. The age of mutation was estimated to be approximately 800 years. These findings characterize Eastern Siberia as the region with the most extensive accumulation of the IVS1+1G>A mutation in the world as a result of founder effect.

Aim of study: To study the reasons of nonsyndromic sensorineural hearing loss, one of frequent hereditary pathologies in the Republic of Sakha (Yakutia), the search of mutations is conducted in the coding region of GJB2 gene in 79 patients from 65 families with a sensorineural hearing loss of III-IV degree (moderate and profound).Results. In GJB2 gene in patients from the Republic of Sakha (Yakutia) we identified 5 different recessive mutations 35delG, V37I, 312-326del14, 333-334delAA, R127H and three sequences variant V27I, M34T, E114G. In Caucasian patients (Russians, Ukrainians, Ingush) the mutations 35delG (41.7%), 312-326del14 (4.2%), 333-334delAA (4.2%) were found. In Yakut patients with non-syndromic sensorineural hearing loss the mutations 35delG (2.1%), V37I (2.1%), R127H (1.0%) and sequences variants V27I (6.3%), M34T (1.0%), E114G (1.0%) were identified. GJB2 mutations were found in 50.1% Caucasians patients and 7.2% Yakut patients.Conclusion. Low frequency of GJB2 mutations in Yakut individuals with non-syndromic sensorineural hearing loss, can testify to the presence in Yakut population of mutations in other genes, responsible for infringement of sound perception process.

Aim. To lead search of mutations by means of the SSCP-analysis in one of coding region of gene GJB2 at patients with sensorineural hearing loss and deafness.Materials and methods. Exit and out-patient medical-genetic consulting clinic of 48 person from 37 unrelated families with the diagnosis sensorineural hearing loss III-IV of a degree. Search possible mutations in locus NO26AU of coding region gene GJB2 spent by means of the analysis of SSCP-Single Strand Conformation Polymorphism.Results. According to the received data change of mobility of samples of DNA with various conformation polymorphisms are revealed: at 11 patients with nonsyndromic hearing loss and deafness (a mutation 35delG), at a patient with Waardenburg syndrome and in 1-st sample who has been used as the control (type of a mutation is not established). The general frequency of mutations on chromosomes of patients of gene GJB2 (locus CX26AU) has made -0,244 (24, 4 %), that considerably below what in the European populations.Conclusion. Most a major mutation in locus Cx26AU of gene GJB2 at patients with sensorineural hearing loss and deafness in RS (Y) is the mutation 35delG. It is possible to consider the reason of decrease in hearing established at 5 patients on which both chromosomes it has been revealed 35delG. In these families in the future the prenatal DNA-diagnostics is possibly to be held. Considering rather low frequency of mutations in locus CX26AU on chromosomes sick sensorineural hearing loss and deafness in Yakutia in comparison with the European regions the further researches of other loci of genes GJB2 and GJB3 by means of the SSCP-analysis and sequence samples of DNA with the found changes of mobility are necessary.