Peutz-Jeghers syndrome

Peutz-Jeghers, also known as Hereditary Intestinal Polyposis Syndrome, is an autosomal dominant genetic disease characterized by the development of hamartomatous polyps in the gastrointestinal tract.

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Diagnosis

The three main criteria for diagnosis are:

• Family history
• Mucocutaneous lesions causing patches of hyperpigmentation in the mouth and on the hands and feet. The oral pigmentations are the first on the body to appear, and thus play an important part in early diagnosis. Intraorally, they are most frequently seen on the gingiva, hard palate and inside of the cheek. The mucosa of the lower lip is almost invariably involved as well.
• Hamartomatous polyps in the gastrointestinal tract. These are benign polyps with a low potential for malignancy.

Having 2 of the 3 listed criteria indicates a positive diagnosis. The oral findings are consistent with other conditions, such as Addison's disease and McCune-Albright syndrome, and these should be included in the differential diagnosis. Definitive diagnosis requires a histological sample of a polyp.

Genetics

In 1998, a gene was found to be associated with the mutation. On chromosome 19, the gene known as STK11/LKB1^[1] is a possible tumor suppressor gene. It is inherited in an Autosomal Dominant pattern (see Mendelian inheritance) which means that anyone who has PJS has a 50% chance of passing it onto their children.

Presentation

The risks associated with this syndrome include a strong tendency of developing cancer in multiple sites,^[2] especially in the gastrointestinal tract. Other areas include the pancreas, liver, lungs, breast, ovaries, and testicles.

The average age of first diagnosis is 23, but the lesions can be identified at birth by an astute pediatrician. Prior to puberty, the mucocutaneous lesions can be found on the palms and soles. Often the first presentation is as a bowel obstruction from an intussusception; an intussusception is a telescoping of one loop of bowel into another segment.

Most of the data regarding this disorder are from selected family lines and thus the risks endured by those families regarding outcomes may not translate completely to the patient without a familial history.

Prognosis

Almost half of Peutz-Jeghers patients die from cancer by age 57 years, and the cumulative risk of developing a form of cancer associated with Peutz-Jeghers syndrome between ages 15-64 is 93%.^[3]

Screening

Screening for cancers include upper GI endoscopy, enteroclysis, colonoscopy, endoscopic ultrasound, testicular ultrasound.

References

1. ^ UniProtKB/Swiss-Prot entry Q15831 [STK11_HUMAN Serine/threonine-protein kinase 11]. Retrieved on 2007-07-21.
2. ^ Boardman LA, Thibodeau SN, Schaid DJ, et al (1998). "Increased risk for cancer in patients with the Peutz-Jeghers syndrome". Ann. Intern. Med. 128 (11): 896-9. PMID 9634427.
3. ^ eMedicine - Peutz-Jeghers Syndrome : Article by Andrea Duchini, MD. Retrieved on 2007-07-21.