Microdeletion of 22q11.1 is associated with two cases of familial nonsyndromic basal cell carcinoma

Multiple basal cell carcinomas (BCCs) are a hallmark of Gorlin syndrome (nevoid basal cell carcinoma syndrome), which is caused by mutation in the PTCH1 gene on 9q22.3. However, there are several reports of familial cases with multiple BCCs without the associated defects of Gorlin syndrome. The possibility of underlying genetic abnormalities in these familial BCCs has not been explored previously. The present study investigated a possible genetic abnormality in two members of a family with multiple nonsyndromic BCCs. The possibility of Gorlin syndrome in this family was excluded by both the absence of any clinical and radiological features and the lack of mutation in PTCH1. Notably, whole-genome comparative genomic hybridization (CGH) identified a microdeletion in chromosome 22q11.1 in both of the studied cases. A tiling path CGH array of the 22q11.1 region confirmed this microdeletion and mapped it between 14.46 and 14.5 Mb on chromosome 22q. The 34-kb region of this microdeletion includes three annotated genes: LOC644525, LOC100132389, and LOC729057. Although future studies of other families with the hereditary nonsyndromic BCCs are still warranted, this study identified an association between a microdeletion of 22q11.1 and two familial cases of BCC.