CLINICAL PECULIARITIES OF THE NON-SYNDROMIC SENSORINEURAL HEARING LOSS IN CHILDREN OF BELARUS
 
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1
Department of ENT, Belarusian State Medical University, Proezd Slobodskoy 6-202, 220025 Minsk, Belarus
2
Department of Cytoplasmic inheritance, Institute of Genetic and Cytology National Academy of Sciences, Belarus
Publication date: 2020-04-20
 
J Hear Sci 2011;1(2):57–59
 
KEYWORDS
ABSTRACT
Background:
About 100 genes are determined to be involved in hearing loss in humans. Among them the major one is GJB2 coding connexin 26. The deletion of any one of six G nucleotides at positions 30–35, so called 35delG mutation, is most often found in GJB2 gene in Europeans. The aim of the study was: 1) to analyze 35delG mutation’s rate in the large group of children with moderate-to-profound sensorineural hearing loss (SNHL); 2) to determine the influence of risk factors of non– syndromic SNHL.

Materials and Methods:
392 children (aged 3–17) with SNHL from moderate-to-profound were examined. A screening for 35delG, pure – tone audiometry and family interviews were performed. A comparative analysis of gender characteristics, degree of hearing loss and risk factors in three groups of children: 35delG heterozygous, 35delG homozygous and without this mutation were performed. The influence of risk factors of SNHL was statistically estimated by means of R-System.

Results:
Among children with moderate and profound SNHL 45% were homozygous and 15% were heterozygous for 35delG GJB2. The most significant risk factors leading to deafness in group of patients without mutation were perinatal risk factors.

Conclusions:
Our study revealed that single-nucleotide deletion 35delG in GJB2 is the main genetic cause of SNHL in Belarus as it was detected in homo- or heterozygous state in 60% of the patients with SNHL. A molecular analysis for 35delG mutation should be performed in cases of positive family history, severe – profound congenital hearing loss, presence of perinatal risk factors.

 
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