Tatiana G Markova

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Molecular testing for mutations in the connexin 26 gene (GJB2) is a routine diagnostic analysis for subjects with hereditary hearing loss worldwide. However, till now there is no assessment of the diagnostic significance of this analysis for Russian patients, and there are difficulties in interpretation of the results of DNA diagnostics. In the present(More)
One of the topical problems of modern pediatric audiology is early diagnostics of congenital sensorineural loss of hearing in children and their timely rehabilitation. The objective of the present study was to obtain audiological characteristics of sensorineural hearing impairment associated with GJB2 gene mutations in children during the first year of(More)
Search for mutations in the connexin 26 gene (GJB2) is a routine molecular-genetic analysis ofthe hereditary deafness worldwide. However, till now there is no assessment of the diagnostic significance of this analysis for Russian patients, and there are difficulties in interpretation of the results of DNA diagnostics. In the present study, a sample of 705(More)
Three families with branchio-oto-renal syndrome (BOR syndrome) were examined. In one of the families all its members with BOR syndrome had deletion of cytosine in position 759 (759delC) in DNA sequence of EYA1 gene in exone 8. Clinical characteristics of BOR syndrome in the family are given. Molecular-genetic analysis confirmed the diagnosis clinically in(More)
Hypoacusis is a common sensory defect in humans which creates problems in communication. Heredity is essential in etiology of hypoacusis and deafness. Genes PAX3 and MITF were studied in patients with Vaardenburg syndrome in 14 unrelated families. Five mutation defects in the gene PAX3 were found. This provided the final diagnosis of the syndrome in these(More)
The combination of pre-lingual and sensorinerual deafness with skin hyperkeratinization is a relatively rare pathology. Only 11 families affected by this disorder were described in the literature during the last 30 years (from 1975 to 2002). To date, there are no more than 50 cases of this condition known in the world. Modern molecular methods revealed in(More)
Mitochondrial DNA (mtDNA) mutations play an important role in etiology of hereditary hearing loss. In various regions of the world, patients suffer from nonsyndromic sensorineural hearing loss initiated by aminoglycoside antibiotics. Mutations that had been shown as pathogenetically important for hearing function disturbance were identified in mitochondrial(More)
Congenital deafness has the heterogeneous nature and can be underlain by both acquired and genetically determined causes. It has been estimated that the prevalence of clinically manifest forms of congenital deafness amounts to 1 case per 700 births. Half of these patients present with the deafness of genetic origin. One of the most common forms of(More)
Congenital deafness affects 0.05-0.1% children. 90% of them were born from parents with normal hearing. There were no hearing defects in their families. In 70% of deafness cases deafness is the only symptom of the disease and is thought to be non-syndromal. Hypoacusis of unclear etiology may be congenital in 50% cases. Half of cases of severe(More)
A total of 111 unrelated probands and their 8 sibs from Grodno oblast (Belarus) with bilateral isolated sensorineural hearing impairment were studied for the presence of mutations in the connexin 26--GJB2gene. Mutations were detected in 51 probands (46% of the sample). A significantly higher frequency of the GJB2gene mutations was observed in familial cases(More)