Synchronous Basal Cell Carcinoma and Squamous Cell Carcinoma of Nasal Vestibule With Novel Unique Variants Identified by Whole-exome Sequencing.

BACKGROUND/AIM: It is estimated that nonmelanoma skin cancer (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), affects more than 3 million Americans each year. Translation of next-generation sequencing (NGS) data into identification of new potential targets for therapeutic applications may be helpful. Whole-exome sequencing (WES) is a widely used NGS method that involves sequencing the protein-coding regions of the genome. CASE REPORT: We report a case of a 65-year-old female smoker who was found to have two 6 mm lesions in her left nasal vestibule. Biopsies demonstrated synchronous BCC and SCC. The patient underwent surgical excision of both cancers with safe margins followed by plastic reconstruction. WES was performed on both cancers and 16 alterations including BRCA2 (p.P389S), FAM5C (S420L), KMT2A (P855L), and SMO (L412F), as unique for BCC, and 4 alterations including TP53 (p.H179Q) and CDKN2A (p.P114L), as unique for SCC, were identified. CONCLUSION: We report the first documented case with unique genetic alterations in two distinct and synchronous skin BCC and SCC arising from the same nasal vestibule of a patient. This adds to the growing field of data regarding genetic variants in characterizing malignancies and potentially for targeted therapies.

Liddle Syndrome due to a Novel c.1713 Deletion in the Epithelial Sodium Channel ß-Subunit in a Normotensive Adolescent.

OBJECTIVE: Liddle syndrome (LS) is a rare autosomal dominant condition secondary to a gain-of-function mutation affecting the epithelial sodium channels (ENaCs) in the distal nephron. It presents with early-onset hypertension, hypokalemia, and metabolic alkalosis in the face of hyporeninemia and hypoaldosteronism. We report a novel mutation affecting the ENaCs in a normotensive adolescent with LS. METHODS: We describe a pediatric case of LS with a novel mutation and review the condition's presentation and management. To date, 31 different mutations in the ß- or γ-subunit of ENaCs have been reported as associated with LS. RESULTS: We describe a 16-year-old girl presenting with muscle cramps with a strong family history of hypertension and hypokalemia. Initial investigations revealed hypokalemia together with hypoaldosteronism and hyporeninemia. Subsequent genetic testing revealed a novel mutation in SCNN1B (deletion: c.1713delC), leading to the premature termination of the sodium channel epithelial 1 subunit-ß protein and the LS phenotype. Treatment with triamterene (50 mg, twice daily) and potassium chloride (20 mEq, once daily) normalized the serum potassium and led to resolution of her muscle cramps. CONCLUSION: It is essential to consider investigating the presence of rare genetic syndromes, like LS, when a patient presents with hypokalemia. Further studies are needed to understand the variable presentation of this condition.