Summary
Peutz-Jeghers syndrome is a hamartomatous polyposis of the entire digestive tract associated with labile lentigines in the mucous membrane of the mouth, anal area and fingers. It confers a higher risk for tumors of the ovary (granulosa cell tumor), testicle (of Sertoli cell origin), cervix and pancreas, and a possible higher risk for cancer of the breast and of the thyroid. It is a rare affection with a prevalence of under 1/50,000. Current data suggests that at least two genes may be involved: the recently identified STK11 gene (19p13.3), is responsible for the disease in 70% of families. It encodes a protein related to the serine-threonine kinases and its biallelic inactivation in hamartomatous lesions suggests it plays a tumor supressor role, a new mechanism for a protein kinase gene. The second gene has not yet been localized. Mutations involve the whole coding sequence, but current knowledge of the spectrum of constitutive mutations does not allow the type or position of mutations to be correlated with their pathological consequences. However, carriers of a familial mutation may be offered specific surveillance based on a diagnostic genetic test. A standard protocol is currently being defined to homogenize screening practices in the near future. *Author: Dr S. Olschwang (February 2005)*.
