[Phenotype of patients showing hearing impairment based on the 35delG mutation in the connexin 26 gene].
BACKGROUND
Hereditary hearing impairment constitutes a heterogeneous class of disorders showing different patterns of inheritance and involving multiple genes. Mutations in the GJB2 gene, especially the 35delG mutation, have been established as a major cause of inherited and sporadic nonsyndromic hearing impairment in different populations.


METHODS
We analyzed 14 northeast Hungarian families and 69 sporadic cases with nonsyndromic hearing impairment for the 35delG mutation. Sixty-five patients showing a homozygous 35delG mutation were examined regarding their audiologic phenotype.


RESULTS
In general, these patients (70%) showed a prelingual, sensorineural, bilateral, symmetric hearing impairment without progression. The audiograms demonstrated sloping as well as flat patterns.


CONCLUSIONS
The severity of hearing impairment varied in 30% of all analyzed patients, making genetic counseling difficult.
Tóth
T
T
Hals-Nasen-Ohren-Klinik, Universität Debrecen (Ungarn).
Kupka
S
S
Sziklai
I
I
Blin
N
N
Zenner
H-P
HP
Pfister
M
M
D000158:Acoustic Impedance Tests; D000293:Adolescent; D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D002648:Child; D002675:Child, Preschool; D002872:Chromosome Deletion; D018388:Codon, Terminator / Q000235:genetics; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D004252:DNA Mutational Analysis; D003638:Deafness / Q000175:diagnosis / Q000235:genetics*; D018450:Disease Progression; D005260:Female; D016368:Frameshift Mutation / Q000235:genetics; D006580:Genetic Carrier Screening; D006147:Guanine / Q000378:metabolism; D006720:Homozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype
D018388:Codon, Terminator; D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26; D006147:Guanine