Gorlin syndrome is a genetic, or hereditary, disease that is caused by changes in two different genes. These genes are called PTCH1 and SUFU, and they encode two corresponding proteins. They are part of a signaling pathway that enables cells to respond to external signals. Now if there is an alteration in one of these genes, this also changes the corresponding protein, and the signaling pathway will no longer function correctly. This malfunction leads to the development of malformations or tumors.
For this reason, part of the diagnostics involves searching for mutations, or changes in the hereditary material, in one of the genes. This greatly depends on which of the two genes is affected: Changes in PTCH1 more often lead to basal cell carcinomas and cysts in the jaw, while mutations in SUFU result in the development of medulloblastomas much more frequently.
Gorlin syndrome occurs in approx. one in 30,000-57,000 people and is passed on by parents to their children in 70-80% of cases. Heredity is autosomal dominant in these cases, with a penetrance of nearly 100%, meaning that nearly every person who has the gene defect ends up suffering from Gorlin syndrome. However, not every patient develops a malignant tumor. The remaining 20-30% of cases are due to a spontaneous or new mutation, called a de novo mutation.