Mutations in the GJB2 gene are associated with
hereditary hearing loss. Although most studies of GJB2
mutations have dealt with hearing-impaired patients, there
are few reports of the frequency of these mutations in the
general population. The purpose of this study is to evaluate
the prevalence of GJB2 mutations causing inherited deafness in the general Korean population. Blood samples were
obtained from 2,072 newborns with normal hearing. The
dried blood samples were subjected to PCR to amplify the
entire coding region of the GJB2 gene, which was followed
by direct DNA sequencing. A total of 24 different sequence
variants were identified in the coding region of GJB2,
including eight pathogenic mutations (p.V37I, p.G45E,
p.R143 W, c.176_191del16, c.235delC, c.292_298dup7,
c.299_300delAT and c.605ins46), four polymorphisms
(p.V27I, p.E114G, p.G160S and p.I203T), six unclassified
variants (p.G4D, p.S85Y, p.T123 N, p.R127H, p.A171T
and p.F191L) and six novel variants (p.W3T, p.I20L,
p.K41E, c.147C [ T, c.186C [ T and c.576A [ G).
Pathogenic mutations causing inherited deafness were
identified in 3% (62/2,072) of the newborns with normal
hearing. Of the eight pathogenic mutations found, p.V37I
was the most common (1.35%, 28/2,072), followed by
c.235delC (1.25%, 26/2,072). These data provide information about carrier frequency for GJB2-based hearing
loss and have important implications for genetic diagnostic
testing for inherited deafness in the Korean population.

EB00000003596K

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• Carrier frequency of GJB2 (connexin-26) mutations causing inherited deafness in the Korean population