Ordering Recommendation

Preferred initial diagnostic and predictive test for PTEN-related disorders.

Mnemonic
PTEN FGA
Methodology

Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification

Performed

Varies

Reported

28-35 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Lavender (K2EDTA), Pink (K2EDTA), or Yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 2 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions
Remarks
Stability

Ambient: 1 week; Refrigerated: 1 month; Frozen: 6 months

Reference Interval
Interpretive Data

Background Information for: PTEN-Related Disorders (PTEN) Sequencing and Deletion/Duplication
Characteristics of PTEN hamartoma tumor syndrome (PHTS):
Clinical findings are highly variable and include Cowden syndrome (CS), Bannayan-Riley-Ruvalcaba syndrome (BRRS), Proteus syndrome (PS), and Proteus-like syndrome (PSL).
CS: Multiple hamartoma syndrome with increased risk for malignant and benign tumors of the breast, thyroid, and endometrium. Other associated findings include macrocephaly and mucocutaneous lesions (facial trichilemmonas, palmoplantar keratoses, and papillomatous papules).
BRRS: Characterized by macrocephaly, intestinal hamartomatous polyposis, lipomas, hemangiomas, and pigmented macules of the glans penis.
PS: A progressive disorder demonstrating mosaic distribution of associated lesions. Findings include hamartomatous tissue overgrowth, hyperostoses, connective tissue and epidermal nevi, dysregulated adipose tissue, vascular malformations, and other congenital malformations.
PSL: Describes individuals with significant features of PS who do not meet clinical diagnostic criteria for PS.
Incidence:
At least 1 in 200,000 for CS; PS is rare with approximately 120 reported cases; unknown for other PTEN-associated conditions. 
Inheritance:
Autosomal dominant. All mutations causing PS and 50-90 percent causing CS are de novo.
Penetrance:
99 percent by 30 years of age for CS. 
Cause:
Pathogenic PTEN gene mutations.
Clinical Sensitivity:
85 percent for CS, 65 percent for BRRS, 50 percent for PSL, and 20 percent for PS.
Methodology:
Bidirectional sequencing of the PTEN promoter, coding region and intron-exon boundaries. Multiplex ligation-dependent probe amplification (MLPA) to detect large PTEN coding region deletions/duplications.
Analytical Sensitivity and Specificity of Sequencing:
99 percent.
Analytical Sensitivity and Specificity of MLPA:
90 and 98 percent, respectively.
Limitations
: Diagnostic errors can occur due to rare sequence variations. Some regulatory region mutations, deep intronic mutations and large deletions of exon 3 may not be detected. Breakpoints for large deletions/duplications will not be determined. 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.

Compliance Category

Laboratory Developed Test (LDT)

Note
Hotline History
N/A
CPT Codes

81321; 81323

Components
Component Test Code* Component Chart Name LOINC
2002471 PTEN FGA Specimen
2002473 PTEN-Related Disorders, Seq and Del/Dup
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • Bannayan-Riley-Ruvalcaba Syndrome (BRRS)
  • PTEN sequencing and deletion/duplication assay
PTEN-Related Disorders (PTEN) Sequencing and Deletion/Duplication