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In oral cavity, the spectrum of diseases due to genetic alterations ranges from developmental disturbances of teeth to the pre-cancerous and cancerous lesions. Of late, significant progress has been made in the molecular analysis of tumors. With molecular genetic testing emerging as diagnostic, prognostic, and therapeutic approach, a review of genetic alterations ranging from the development of oro-facial structures to the tumors in the head and neck region are addressed in this article. The functional regulatory aspect of genes in relation to oro-facial structures are discussed separately, i.e., in relation to tooth genesis, tooth agenesis (non-syndromic, syndromic), tooth structural alterations, syndromic oro-facial defects, bone diseases, skin diseases (genodermatoses), and malignant tumors. In this literature, various genes involved in the development of the oro-facial structures and tooth in particular are discussed. The genetic basis of disorders in the tooth development (agenesis, hypodontia), tooth structural defects like amelogenesis imperfecta (AI), dentinogenesis imperfecta (DI), and oro-facial structural alterations (various syndromes) are explained.

Background Gain‐of‐function of ATP‐sensitive K+ (KATP) channels because of mutations in the genes encoding SUR1 (ABCC8) or Kir6.2 (KCNJ11) is a major cause of neonatal diabetes mellitus (NDM). Our aim is to determine molecular defects in KATP channels caused by ABCC8 mutations in Asian Indian children with NDM by in vitro functional studies. Methods Wild‐type (WT; NM_000352.4) or mutant sulfonylurea receptor 1 (SUR1) and Kir6.2 were co‐expressed in COSm6 cells. Biogenesis efficiency and surface expression of mutant channels were assessed by immunoblotting and immunostaining. The response of mutant channels to cytoplasmic ATP and ADP was assessed by inside‐out patch‐clamp recordings. The response of mutant channels to known KATP inhibitors in intact cells were determined by 86Rb efflux assays. Results Five SUR1 missense mutations, D212Y, P254S, R653Q, R992C, and Q1224H, were studied and showed increased activity in MgATP/MgADP. Two of the mutants, D212Y and P254S, also showed reduced response to ATP4− inhibition, as well as markedly reduced surface expression. Moreover, all five mutants were inhibited by the KATP channel inhibitors glibenclamide and carbamazepine. Conclusions The study shows the mechanisms by which five SUR1 mutations identified in Asian Indian NDM patients affect KATP channel function to cause the disease. The reduced ATP4− sensitivity caused by the D212Y and P254S mutations in the L0 of SUR1 provides novel insight into the role of L0 in channel inhibition by ATP. The results also explain why sulfonylurea therapy is effective in two patients and inform how it should be effective for the other three patients.

Carcinoma cuniculatum is one of the variants of squamous cell carcinoma. It is significantly rare with an incidence rate < 1% compared to other histological variants of squamous cell carcinoma. Various etiologic factors implicated are trauma, HPV, chronic inflammation and alcohol consumption but real causative agent still remains unclear. Initially it resembles plantar wart which slowly progress to bulky exophytic mass in the sole of the foot, where cases have been reported first. In the oral cavity it presents clinically as an exophytic growth and slowly invades the jaw and destroys the underlying bone. Microscopically it exhibits as both exophytic and endophytic epithelial masses along with well differentiated and pronounced hyperkeratosis. Treatment includes surgical resection alone unlike other variants which are treated by radiation with or without chemotherapy. Here we present a case of carcinoma cuniculatum occurred in alveolar mucosa of a 47 years old female. It presented as an exophytic growth in mandibular alveolar region, with histological features consistent with carcinoma cuniculatum.