Variable expression of Gorlin syndrome may reflect complexity of the signalling pathway.

Nevoid Basal Cell Carcinoma Syndrome (NBCCS) or Gorlin syndrome is an autosomal dominant disorder characterized by cancer predisposition and multiple developmental defects. Syndrome related disorders have been attributed to alterations of PTCH gene, which plays an important role in Shh signalling pathway. Unresolved complexities of the pathway impede understanding of mechanisms through which PTCH alterations lead to variable phenotype expression in Gorlin syndrome patients, while the role of chromosomal instability is not yet clear. To increase our understanding of NBCCS, every manifestation of the syndrome and associated genetic damage should be seriously considered. Therefore, several atypical NBCCS cases are presented in this paper.