Assessment of the genetic causes of recessive childhood non-syndromic deafness in the UK - implications for genetic testing.
Approximately one in 2000 children is born with a genetic hearing impairment, mostly inherited as a non-syndromic, autosomal recessive trait, for which more than 30 different genes have been identified. Previous studies have shown that one of these genes, connexin 26 (GJB2), accounts for 30-60% of such deafness, but the relative contribution of the many other genes is not known, especially in the outbred UK population. This lack of knowledge hampers the development of diagnostic genetic services for deafness. In an effort to determine the molecular aetiology of deafness in the population, 142 sib pairs with early-onset, non-syndromic hearing impairment were recruited. Those in whom deafness could not be attributed to GJB2 mutations were investigated further for other mapped genes. The genetic basis of 55 cases (38.7%) was established, 33.1% being due to mutations in the GJB2 gene and 3.5% due to mutations in SLC26A4. None of the remaining 26 loci investigated made a significant contribution to deafness in a Caucasian population. We suggest that screening the GJB2 and SLC26A4 genes should form the basis of any genetic testing programme for childhood deafness and highlight a number of important issues for consideration and future work.
Hutchin
T
T
Molecular Medicine Unit, St James's University Hospital, University of Leeds, UK. tim-hutchin@bch.nhs.uk
Coy
N N
NN
Conlon
H
H
Telford
E
E
Bromelow
K
K
Blaydon
D
D
Taylor
G
G
Coghill
E
E
Brown
S
S
Trembath
R
R
Liu
X Z
XZ
Bitner-Glindzicz
M
M
Mueller
R
R
D000070585:Cadherin Related Proteins; D015820:Cadherins / Q000235:genetics; D002675:Child, Preschool; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D004252:DNA Mutational Analysis; D003638:Deafness / Q000453:epidemiology* / Q000235:genetics*; D016326:Extracellular Matrix Proteins / Q000235:genetics; D058851:GPI-Linked Proteins; D005808:Genes, Recessive / Q000235:genetics; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing / Q000379:methods*; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics; D026901:Membrane Transport Proteins / Q000235:genetics; D009154:Mutation / Q000235:genetics*; D009363:Neoplasm Proteins / Q000235:genetics; D018807:Polymorphism, Single-Stranded Conformational; D011498:Protein Precursors / Q000235:genetics; D012697:Serine Endopeptidases / Q000235:genetics; D000076988:Sulfate Transporters; D006113:United Kingdom / Q000453:epidemiology; D044465:White People
C498835:CDHR15, human; D000070585:Cadherin Related Proteins; D015820:Cadherins; D017630:Connexins; D016326:Extracellular Matrix Proteins; C000607042:GJB2 protein, human; D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D009363:Neoplasm Proteins; C118457:OTOF protein, human; D011498:Protein Precursors; C085609:SLC26A4 protein, human; D000076988:Sulfate Transporters; C491350:TECTA protein, human; D000072259:Connexin 26; D012697:Serine Endopeptidases; C409042:TMPRSS3 protein, human