Keratitis-ichthyosis-deafness (KID) syndrome is a rare genetic disease characterized by deafness, visual impairments, and palmoplantar keratoderma. The disease arises from Connexin26 (Cx26) mutations that lead to the formation of hyperactive hemichannels causing uncontrolled molecule transfer across the membrane. Although the uncontrolled molecule transfer affects the proliferation and differentiation of keratinocytes, the exact molecular and cellular mechanisms underlying the epidermal alterations due to Cx26 mutations are not yet known. Previous studies showed enriched NF-κB pathway members in keratinocyte cell line HaCaT containing Cx26-D50Y KID syndrome mutation. Therefore, we hypothesized that Cx26 mutant channels may cause epidermal disorders by affecting keratinocyte proliferation and differentiation mechanisms via NF-kB pathway. We investigated proliferation and differentiation mechanisms of the HaCaT cells that constitutively express the Cx26-G45E and Cx26-D50Y mutations, which cause different severity. G45E and D50Y containing cells showed the highest nuclear RelA and c-Rel signals, respectively. In addition, NaSal treatment affected early and late apoptosis rates differently in D50Y cells. Moreover, G45E and D50Y cells had opposite trends when early and late apoptosis rates were compared. Furthermore, NF-κB inhibition decreased proliferation rate of G45E cells, unlike WT cells. Lastly, cytokeratin10 protein levels showed differences in G45E cells after NaSal treatment. NF-kB may affect apoptosis in KID syndrome mutants through distinct mechanisms and may have different effects on apoptosis mechanisms of D50Y. Furthermore, NF-kB may regulate proliferation and differentiation mechanisms of G45E. There is no available treatment for KID syndrome yet. Therefore, this study is important to understand the underlying mechanisms of KID syndrome.