Connexin 26 mutation in keratitis-ichthyosis-deafness (KID) syndrome in mother and daughter with combined conductive and sensorineural hearing loss.
BACKGROUND
Keratitis-ichthyosis-deafness (KID) syndrome most commonly results from a mutation in the gap-junctional protein connexin 26 (Cx26) gene, GJB2. Most cases are sporadic and are associated with sensorineural hearing loss.


METHODS
We encountered a mother and daughter with KID syndrome, and pursued genetic analysis and an extensive hearing loss evaluation.


RESULTS
The analysis of genomic DNA of both affected patients revealed the mutation 148G --> A in GJB2 (D50N). No mutation was found in an unaffected son. Auditory phenotype analysis showed a combined conductive and sensorineural hearing loss in both affected patients.


CONCLUSIONS
This is the second vertical transmission of the D50N mutation. These are the first two cases with combined sensorineural and conductive hearing loss without any significant history of middle ear disease. This points to the possibility that the Cx26 D50N mutation can cause conductive hearing loss.
Kelly
Brent
B
University of Texas Medical Branch, Galveston, and Baylor College of Medicine, Houston, Texas, USA. bckelly@utmb.edu
Lozano
Annabelle
A
Altenberg
Guillermo
G
Makishima
Tomoko
T
D000293:Adolescent; D019943:Amino Acid Substitution / Q000235:genetics; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D005799:Genes, Dominant; D006314:Hearing Loss, Conductive / Q000235:genetics*; D006319:Hearing Loss, Sensorineural / Q000235:genetics*; D006801:Humans; D007057:Ichthyosis / Q000235:genetics* / Q000473:pathology; D007634:Keratitis / Q000235:genetics*; D007645:Keratoderma, Palmoplantar / Q000235:genetics* / Q000473:pathology; D008297:Male; D010375:Pedigree; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D012867:Skin / Q000473:pathology; D013577:Syndrome
D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26