Mosaic <i>STIM1</i> Variant Associated with Epidermal Nevus

Epidermal nevi (EN) are mosaic epidermal differentiation disorders caused by postzygotic variants that affect pathways regulating epidermal proliferation, differentiation, and barrier function. We report a young woman with a verrucous EN harboring a somatic mosaic indel variant in STIM1, expanding the molecular spectrum of EN and implicating dysregulated calcium signaling as a novel pathogenic mechanism.