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
Polymerase Chain Reaction/Sequencing
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.
Multiplex Ligation-dependent Probe Amplification
Use to assess for large deletion/duplication previously identified in a family member
- A copy of a relative’s lab report is required
- Consultation with a genetic counselor is advised
See Related Tests
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.
Disease Overview
Prevalence
Symptoms
- 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
Genetics
Gene
Inheritance
Penetrance
De novo Variant(s)
Approximately 45% of affected individuals have no family history of PJS; however, the exact proportion of de novo variants is unknown
Test Interpretation
Sensitivity/Specificity
Clinical sensitivity
- PJS (STK11) sequencing and deletion/duplication
Analytical sensitivity/specificity: 99%
Results
- 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
Limitations
- 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
References
-
NCCN - Genetic/familial high-risk assessment: colorectal v1.2020
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]
Online -
NIH - Peutz-Jeghers syndrome
National Institutes of Health, Genetics Home Reference. Peutz-Jeghers syndrome. [Accessed: Sep 2020]
Online -
24260271
Tchekmedyian A, Amos CI, Bale SJ, et al. Findings from the Peutz-Jeghers syndrome registry of Uruguay. PLoS One. 2013;8(11):e79639.
PubMed -
GeneReviews - Peutz-Jeghers
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]
Online -
20051941
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.
PubMed -
15121768
Amos CI, Keitheri-Cheteri MB, Sabripour M, et al. Genotype-phenotype correlations in Peutz-Jeghers syndrome. J Med Genet. 2004;41(5):327-333.
PubMed -
23415580
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.
PubMed