Cowden Syndrome, Multiple Harmartoma Syndrome: PTEN Sequencing

Diagnostic Use

Cowden disease (CD) also known as multiple hamartoma syndrome is characterised by a range of clinical manifestations including multiple hamartomatous lesions, especially of the skin, mucous membranes, breast and thyroid. Verrucous skin lesions of the face and limbs, cobblestone-like papules of the gingiva and buccal mucosa and multiple facial trichilemmomas are also common. Further manifestations include macroencephaly and hamartomatous polyps of the colon and other intestines. However the most serious problem is the increased risk of malignancies of the bowel, breast, skin, brain and thyroid. Other diseases iso-allelic to Cowden disease i.e. caused by mutations in the PTEN gene, include Lhermitte-Duclos disease, Bannayan Zonana syndrome, Bannayan-Riley-Ruvalcaba syndrome, Proteus syndrome and Proteus-like syndrome. Mutation analysis of the entire coding region of PTEN and its promoter may detect 80% of classic Cowden syndrome (CS), 60% of Bannayan-Riley-Ruvalcaba syndrome (BRRS), up to 20% of Proteus syndrome (PS) and approximately 50% of a Proteus-like syndrome (PSL).

Department

Genetics - Molecular Pathology

Delphic Registration Code

MOLP

Constituent Tests

• Genomic DNA Extraction

Synonyms

Bannayan Zonana
Bannayan-Riley-Ruvalcaba
BRRS
Lhermitte-Duclos
Proteus syndrome

Turnaround Time

4 weeks

Test Code

7312

Specimen Type

• Whole Blood

Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

4.0

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

1.0

Minimum Sample Volume (ml)

0.5

Additional Specimen Information

This genetic test needs nucleated cells. Please don’t centrifuge or freeze the EDTA blood tube.
If storing blood tube prior to delivery please refrigerate at 4 degrees (transport still at ambient temperature).

Aliquot Instructions

Sample Type

• Whole Blood

Transport to Lab

Ambient (8 - 24 degrees Celsius)

Additional Referral/Aliquot Information

This genetic test needs nucleated cells. Please don’t centrifuge or freeze the EDTA blood tube.
If storing blood tube prior to delivery please refrigerate at 4 degrees (transport still at ambient temperature).

Test Method

Patient DNA is analysed using a Twist Biosciences next generation sequencing (NGS) custom panel on an Illumina MiSeq instrument. Coding regions and exon-intron boundaries, plus the promoter region, of the PTEN gene (NM_000314.8) are analysed.

Non-Funded Test Cost

$652.33 (Exclusive of GST)

Billing Code

4564

Uncertainty of Measurement:
Automated bidirectional DNA sequencing has an analytical sensitivity and specificity of >99%. Note that the lower limit of variant detection of sequencing analysis is ~10%, this is important to consider in the case of mosaicism, mitochondrial, and somatic variation that is not expected to be present at 50% or 100%. This analysis will not detect variants located within intronic regions, except at the intron-exon boundaries.

Genomic DNA must be extracted from the specimen prior to testing. This incurs an additional charge (see GDNA). Laboratories may prefer to submit DNA for testing. Please provide a minimum of 5 micrograms of DNA at 20 nanograms/microliter

Contact Information

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