A report of GJB2 (N14K) Connexin 26 mutation in two patients--a new subtype of KID syndrome?

Keratitis-ichthyosis-deafness syndrome is a rare congenital ectodermal disorder, characterized by presence of skin lesions, neurosensory hearing loss, and vascularizing keratitis. Several autosomal dominant mutations in the Connexin 26 gene (GJB2) have been discovered as a cause of this syndrome. We report two patients who presented with a combination of clinical features of keratitis-ichthyosis-deafness syndrome (e.g., congenital bilateral neurosensory hearing loss and erythrokeratoderma), however, lacking other characteristics typical of this condition. In addition, they both demonstrated striking mucocutaneous findings (e.g., chronic lip fissuring, gingival hyperemia), resulting in diagnostic difficulties. In both patients, a GJB2 mutation (N14K) was identified, which shares the same gene with classic Keratitis-ichthyosis-deafness syndrome but has never been described in patients with this condition. We propose that the findings observed in our patients are a distinct subtype of Keratitis-ichthyosis-deafness syndrome, thus expanding the spectrum of connexin-associated keratodermias.