Chromosome 9 mutations reported absent in some patients with basal cell carcinoma nevus syndrome

Clarifying the Current Understanding of Syndromic Basal Cell Carcinomas

“…Although they concluded that BCNS-BCCs show better therapeutic response than sporadic BCCs to Smoothened inhibitors (SIs) because of lower mutational load, it is important to note that some patients with BCNS do not carry PTCH1 mutations and therefore may not respond to SIs. In fact, we previously reported that 10e12% of genetically tested patients with BCNS failed to have chromosome 9/PTCH1 mutations despite meeting the clinical criteria for BCNS (Shih et al, 2018). Moreover, only 28.5% of 288 patients with BCNS received genetic testing for chromosome 9/PTCH1 mutations, though the types of mutations were not specified (Shih et al, 2018).…”

“…In fact, we previously reported that 10e12% of genetically tested patients with BCNS failed to have chromosome 9/PTCH1 mutations despite meeting the clinical criteria for BCNS (Shih et al, 2018). Moreover, only 28.5% of 288 patients with BCNS received genetic testing for chromosome 9/PTCH1 mutations, though the types of mutations were not specified (Shih et al, 2018). We want to highlight the importance of genetic testing before initiating SI therapy, because patients with BCNS with germline mutations in non-PTCH1 genes, such as SUFU, are unlikely to respond to SIs (Smith et al, 2014;Varjosalo and Taipale, 2008).…”