Yangyang Hao ¹ Rong Wu ² Xi Chen ¹ Yunjia Shen ¹ Mengwei Chou ¹ Jianqiang YANG ^1*

• ¹ Department of Dermatology, The First People's Hospital of Huzhou, Huzhou, China
• ² Department of Orthopedic Surgery, The First People's Hospital of Huzhou, Huzhou, China

Olmsted syndrome (OS) is a rare congenital skin disorder, typically characterized by symmetrical, severe palmoplantar and periorificial keratoderma, often accompanied by alopecia, and onychodystrophy, with varying degrees of pruritus and pain. Gain-of-function variants of the transient receptor potential cation channel subfamily V member 3 (TRPV3) were described as a cause of OS. Here, we report an atypical case of OS caused by a novel mutation in TRPV3 gene that has not been described before in OS. The patient presented with disabling, bilateral palmoplantar keratoderma, and subsequently developed squamous cell carcinoma on the right sole. Genetic analysis identified a novel heterozygous p.Val306Met missense mutation in the exon 8 of TRPV3. Our findings expand the phenotypic spectrum of TRPV3-related OS and underscore the need for vigilant long-term monitoring of these patients.