Moderate hearing loss and pseudodominant inheritance due to L90P/35delG mutations in the GJB2 (connexin 26) gene.
Mutations in the GJB2 (connexin 26-Cx26) gene are responsible for 20-50% of cases with prelingual non-syndromic deafness in a large part of the world including Turkey. Although most of the cases with Cx26 deafness have a recessive mode of inheritance, a small group of families demonstrated dominant or pseudodominant inheritance. In this report we present a Turkish family in which the proband had congenital profound deafness and was found to be homozygous for the 35delG mutation, whereas the father and a paternal uncle who had milder, late-onset sensorineural hearing loss had compound heterozygous 35delG and L90P mutations. This family and previous reports with the L90P mutation demonstrate that the hearing loss associated with the L90P/35delG genotype is consistently milder than that of 35delG homozygotes. GJB2 gene screening should be considered in families with seemingly dominant inheritance and late-onset moderate hearing loss.
Tekin
M
M
Division of Pediatric Molecular Pathology and Genetics, Ankara University School of Medicine, Ankara 06 100, Turkey. mtekin@medicine.ankara.edu.tr
Duman
T
T
Boğoçlu
G
G
Incesulu
A
A
Cin
S
S
Akar
N
N
D000328:Adult; D002675:Child, Preschool; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D005260:Female; D005817:Genetic Counseling; D006319:Hearing Loss, Sensorineural / Q000235:genetics*; D006801:Humans; D040582:Inheritance Patterns; D008297:Male; D009154:Mutation; D010375:Pedigree; D014421:Turkey
D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26