Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification
- Preferred test to confirm diagnosis of PJS in symptomatic individual
- Use for disease prediction in presymptomatic individual with family history of PJS
Recommended test for a known familial sequence variant previously identified in a family member
- A copy of the family member’s test result documenting the familial variant is required
- Consultation with a genetic counselor is advised.
Peutz-Jeghers syndrome (PJS) is characterized by the development of noncancerous growths called hamartomatous polyps in the gastrointestinal tract (particularly the stomach and intestines) and an increased risk of developing certain types of cancer. Malignant tumors are most commonly found in the gastrointestinal tract, pancreas, cervix, ovary, and breast; management guidelines have been published by the National Comprehensive Cancer Network (NCCN). Polyps may also result in associated noncancerous health problems, including recurrent bowel obstructions, chronic bleeding, and abdominal pain. Children with PJS may also develop dark colored spots (hyperpigmentation) on face and body, which may fade with age.
- GI polyposis, including hamartomatous PJS-type polyps, resulting in :
- Chronic bleeding, anemia, recurrent obstruction, intussusception
- Adenomatous polyps in colon, small intestine, stomach, large bowel, nasal passages
- Hyperpigmentation presenting as dark blue to brown macules around mouth, eyes, nostrils, perianal area, buccal mucosa, fingers
- Increased risk for intestinal and extraintestinal malignancies: colorectal, gastric, pancreatic, breast, sex cord tumors in ovary or testes, adenoma malignum of cervix, uterine, and lung
- Lifetime risk for any cancer varies between 37-93%
Age of Onset
- Hyperpigmented macules most pronounced before age 5; not usually present at birth
- Median age for gastrointestinal (GI) symptoms is 10 years
De novo Variant(s)
- PJS (STK11) sequencing and deletion/duplication
Analytical sensitivity/specificity: 99%
- Positive: diagnosis confirmed
- Negative: diagnosis of PJS is less likely but not excluded
- Uncertain: gene variant detected, but whether the variant is benign or pathogenic is unclear
- Regulatory region and deep intronic variants will not be detected
- Large deletion/duplication breakpoints will not be determined
- Diagnostic errors can occur due to rare sequence variations
- This assay is not designed to detect somatic variants associated with malignancy
- Interpretation of this test result may be impacted if the patient has had an allogeneic stem cell transplantation
National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology, genetic/familial high-risk assessment: colorectal, Version 1.2020. [Updated: Jul 2020; Accessed: Feb 2021]
National Institutes of Health, Genetics Home Reference. Peutz-Jeghers syndrome. [Accessed: Sep 2020]
Tchekmedyian A, Amos CI, Bale SJ, et al. Findings from the Peutz-Jeghers syndrome registry of Uruguay. PLoS One. 2013;8(11):e79639.
McGarrity TJ, Amos CI, Baker MJ. Peutz-Jeghers syndrome. In: Adam MP, Ardinger HH, Pagon RA, et al, eds. GeneReviews. University of Washington, Seattle; 1993-2021. [Updated: Jul 2016; Accessed: Feb 2021]
van Lier MG, Wagner A, Mathus-Vliegen EM, et al. High cancer risk in Peutz-Jeghers syndrome: a systematic review and surveillance recommendations. Am J Gastroenterol. 2010:1258-1264.
Amos CI, Keitheri-Cheteri MB, Sabripour M, et al. Genotype-phenotype correlations in Peutz-Jeghers syndrome. J Med Genet. 2004;41(5):327-333.
Resta N, Pierannunzio D, Lenato GM, et al. Cancer risk associated with STK11/LKB1 germline mutations in Peutz-Jeghers syndrome patients: results of an Italian multicenter study. Dig Liver Dis. 2013;45(7):606-611.