ACTB Mutations Analysis and Genotype–Phenotype Correlation in Becker’s Nevus

Abstract

Becker’s nevus (BN) is a cutaneous hamartoma which is characterized by circumscribed hyperpigmentation with hypertrichosis. Recent studies have revealed that BN patients harbored postzygotic ACTB mutations, which were restricted to arrector pili muscle lineage. We screened for ACTB mutations in 20 Chinese patients with BN and found that recurrent mutations (c.C439A or c.C439T) in ACTB were detected in the majority of BN patients. However, more than 20% of the patients were negative for ACTB mutations, suggesting a possible genetic heterogeneity in Becker’s nevus. Interestingly, these mutations were also detected in dermal tissues outside the arrector pili muscle. We further performed genotype–phenotype correlation analysis, which revealed that lesions above the waistline, including the trunk above the anterior superior spine level, upper limbs and face, or covering more than 1% BSA were more likely to be positive for ACTB mutations. Altogether, our results provide further evidence of postzygotic ACTB mutations in BN patients and suggest a possible genotype–phenotype correlation of BN.

An update on Becker's nevus: Pathogenesis and treatment

“…In 2021, Dai discovered ACTB mutations in dermal tissues other than the arrector pili muscle, suggesting that the arrector pili muscle is not the only source of ACTB mutations in BN. The study showed that patients with skin lesions covering more than 1% body surface area or located above the waist were more likely to carry ACTB mutations 22 …”

“…The study showed that patients with skin lesions covering more than 1% body surface area or located above the waist were more likely to carry ACTB mutations. 22…”