Patching Together the Genetics of Gorlin Syndrome

Abstract

Background: Gorlin syndrome is an autosomal dominant disorder characterized by developmental defects and susceptibility to cancer, especially to basal cell carcinomas. The genetic basis of this disorder has recently been elucidated. Methods: In this article previous studies are reviewed in which loss of heterozygosity analysis of tumours and normal tissue pointed to a region on chromosome 9 as being involved in Gorlin syndrome. In this light, Knudson's two-hit model is discussed. The identification of the involvement of the patched gene in Gorlin syndrome is reviewed. New data on genotype-phenotype correlations in the syndrome are presented. Results: Loss-of-heterozygosity studies, together with standard family studies using linkage analysis, have proved useful in identifying the location of a gene with complex phenotypic expression. Conclusion: The application of the two-hit model, as utilized in loss-of-heterozygosity studies, has been very useful in elucidating the genetic basis of Gorlin syndrome. There may be a correlation between certain aspects of the mutations in patched and the clinical presentation of the disorder in families.