BRAF mutations in multiple sebaceous hyperplasias of patients belonging to MYH-associated polyposis pedigrees

Giovanni Ponti, Tiziana Venesio, Lorena Losi, Giovanni Pellacani, Lucio Bertario, Paola Sala, Monica Pedroni, Consalvo Petti, Stefania Maffei, Liliana Varesco, Erika Lerch, Andrea Baggio, Sara Bassoli, Caterina Longo, Stefania Seidenari

Research output: Contribution to journalArticlepeer-review


The characteristics of sebaceous gland hyperplasia (SGH) consist of yellowish or skin-colored papules and nodules. Chronic sun exposure and immunosuppressed conditions are the main environmental risk factors, whereas chronological aging regulated by hormones and molecular changes are the intrinsic risk factors. We have evaluated the contribution of BRAF, K-Ras, and N-Ras mutations to the pathogenesis of SGHs in four patients belonging to three MYH-associated polyposis (MAP) pedigrees. MAP is an autosomal-recessive disease characterized by multiple colorectal adenomas and cancer. Immunohistochemistry of mismatch repair and APC proteins was performed. DNA isolated from blood lymphocytes and formalin-fixed or paraffin-embedded SGHs was PCR amplified and sequenced. In the SGH patients, we detected T1796A heterozygous substitution (V600E) in the BRAF gene. Compound biallelic germline MYH mutations (Y165C/G382D, R168H/379delC, and Y90X/delGGA464) were detected in the MAP patients. In contrast to the majority of melanocytic lesions, activating hotspot mutations in BRAF have not been involved so far in the pathogenesis of SGH. BRAF mutation is not a specific marker of melanocytic cancerogenesis, and it can also be involved in SGHs. In both melanocytic and non-melanocytic skin tumors, BRAF mutation is linked to early tumorigenesis events.

Original languageEnglish
Pages (from-to)1387-1391
Number of pages5
JournalJournal of Investigative Dermatology
Issue number6
Publication statusPublished - Jun 2007

ASJC Scopus subject areas

  • Dermatology


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