Discovery of a Novel Hemizygous c.375_389del Variant in the MBTPS2TPS2 Gene in a Male Patient

Keratosis follicularis spinulosa decalvans (KFSD) is a rare predominantly X-linked disorder typically associated with MBTPS2 variants and characterized by follicular keratosis, cicatricial alopecia, and variable ocular involvement. We describe a 32-year-old male with a novel hemizygous MBTPS2 variant (c.375_389del), presenting with ulerythema ophryogenes, erythromelanosis faciei et colli, widespread keratosis pilaris, and multiple facial epidermoid cysts. This report highlights overlapping phenotypic features across the keratosis pilaris atrophicans spectrum and expands the clinical manifestations linked to MBTPS2 mutations.