Authors: Martin Koenighofer Trevor Lucas Thomas Parzefall Reinhard Ramsebner Christian Schoefer Klemens Frei
Publish Date: 2014/08/02
Volume: 272, Issue: 1, Pages: 229-232
Abstract
The objective of this study was to investigate the relevance of routine assessment of c−259CT in the Austrian newborn screening program Homozygous and compound heterozygous mutations in the coding region of the human gene encoding gap junction protein GJB2 Connexin 26 cause up to 50 of neonatal autosomal recessive nonsyndromic hearing impairment identified in Caucasian newborn screening programs More recently a null mutation in the GC box of the GJB2 basal promoter c−259CT has been described which causes hearing impairment by completely suppressing GJB2 promoter activity We determined the occurrence of c−259CT in cases of nonsyndromic hearing impairment lacking known pathogenic alterations in GJB2 n = 43 a nonsyndromic hearing impaired patient group n = 15 bearing the heterozygous GJB2 mutations c35delG c79GA341AG p V27IE114G c109GA pV37I c154GC pV52L c262GT pA88S c269TC pL90P and c551GC pR184P and in a normal hearing group lacking alterations in GJB2 n = 50 In the analyzed groups no occurrence of c−259CT was found The c−259CT mutation previously described as −3438CT is not a common cause of nonsyndromic hearing impairment alone or together with heterozygous pathogenic GJB2 mutations that are statistically overrepresented in nonsyndromic hearing impaired patient groups Screening of newborns for c−259CT is therefore unlikely to be commonly found in Austrian NSHI patients but could make a significant contribution to nonsyndromic hearing impairment in other populations
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