Peutz-Jeghers Syndrome : Pathogenesis
Pathogenesis of Peutz-Jeghers Syndrome (PJS): PJS is an autosomal dominant syndrome with incomplete and variable penetrance. About 50% of PJS patients have loss-of-function heterozygous mutations in a tumor suppressor gene STK11 (also known as LKB1) on chromosome 19p. It codes for serine/threonine kinase 11 – an enzyme that has a role in cell polarity, regulates cell growth and anabolism, and promotes apoptosis. The loss of second (normal) copy of the gene via somatic mutations leads to uncontrolled cell growth and results in cancers seen in PJS. The absence of STK11 mutation does not exclude the possibility of PJS. The image shows a microabscess in distorted glands of a PJS colon polyp.