19th July 2023

Peutz-Jeghers Syndrome (PJS)

PJS is a rare condition characterised by multiple hamartomatous polyps throughout the GI tract, most commonly affecting the jejunum. It is caused by a mutation in the STK11 gene, 50% occurring de novo and 50% inherited in an autosomal dominant fashion. Around 50% of patients will present in their 1st or 2nd decade of life with bowel obstruction. Other symptoms include GI bleeding (overt or presenting as iron deficiency anaemia), abdominal pain and distension. A hallmark sign is pigmented macules on the buccal mucosa, perioral areas, lips, fingers and toes. Diagnosis is confirmed with genetic testing. Polyps can be resected under endoscopic guidance. Patients have a 93% lifetime risk of malignancy – intestinal most commonly (39% colorectal cancer, 19% small bowel cancer) but also extra-intestinal (breast, pancreatic and ovarian/testicular cancer).