INGEBI   02650
INSTITUTO DE INVESTIGACIONES EN INGENIERIA GENETICA Y BIOLOGIA MOLECULAR "DR. HECTOR N TORRES"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Spectrum and frequencies of mutations in GJB2 and GJB6 among Argentinean patients with sensorineural non-syndromic deafness.
Autor/es:
DALAMON, VIVIANA; WERNERT, M. FLORENCIA; ELGOYHEN, A. BELEN
Lugar:
Baltimore, Maryland, USA
Reunión:
Congreso; Association for Research in Otolaryngology (ARO); 2011
Institución organizadora:
Association for Research in Otolaryngology (ARO)
Resumen:
Genetically caused
congenital deafness is a common trait affecting 1 in 2000 children. Most cases
are non-syndromic and of autosomal recessive inheritance. To date, over 40
different genes have been identified as genetic cause of deafness worldwide.
The aim of this study was to investigate and report the spectrum and frequency
of mutations in GJB2, GJB6, OTOF and MT-RNR1, in deaf patients from
Argentina. A total of 773 samples were analyzed; 439 from non-syndromic
unrelated Argentinean deaf patients (99 familial and 340 sporadic cases) and 334
from relatives and siblings. Most of them were of prelingual onset (83%). At the
time of the study 78 patients were already cochlear implanted.
Mutations in GJB2
and GJB6 genes were found in 156 patients, accounting for 36% of the
sample. Overall 38 different sequence variations were identified. The mutation
c.35delG accounted for 55/439 (13%) of the patients studied, resulting in 35%
of the detected mutations, becoming the most frequent causing mutation in our
population, in accordance with other reports worldwide. Only 2% of patients
showed mutations in the GJB6 gene (seven del(GJB6-D13S1830) and three del(GJB6-D13S1854)).
In addition, 35 sequence variations different from c.35delG, were identified in
the GJB2 gene: T8M, L10P, G12V, S19T, V27I, M34T, V37I, E47X, 167delT, R75W, R75Q, c.233 insG, W77R, I82M, F83L, V84L, L90P, c.269insT, V95M, c.312del14nt, G109V, c.333delAA, R127H,
I128I, E129K, R143W, V153I, G160S, M163V, M163L, K168R, R184P, V190D, c.682 C>T (3´UTR), IVS1+1G>A. Four of them are reported for the first time (L10P, c.233 insG, G109V and V190D). None of the samples showed mutations either in OTOF or in MT-RNR1.
The present study
demonstrates that different mutations in the GJB2 and GJB6 genes
are prevalent in our Argentinean population. These findings strengthen the
importance of genetic screening in hearing-impaired patients for the
contribution towards an adequate genetic counseling and treatment planning.