Genetic Testing for PLN-Associated Variant Genes

After years of research supported by hundreds of Wheatens and their owners and breeders, Dr. Meryl Littman and Dr. Paula Henthorn at the University of Pennsylvania School of Veterinary Medicine (Penn Vet) identified mutations associated with PLN in two genes.

This project has implications throughout the Wheaten world, and any owner or breeder can participate in this Research.

A simple cheek swab test (two swabs for each dog) is used to determine an individual dog’s DNA status. Litters can also be tested, as can frozen Semen.

Details of costs, information guides and how to obtain swabs, from The SCWT Club of America.

If you live in the UK, swabs for either Penn or Laboklin can be obtained from Judy Creswick at this email address of The SCWT Club of GB.

For the PLN-Variant Genes Test it is preferred that Penn Laboratory (PennGen) is used as this enables continuity of research. In Europe and Scandinavia Laboklin Laboratories also offer the test but the result does not directly aid this research.

Test Results definitions (updated August 2017)

This table clarifies the reporting formats between PennGen and Laboklin test results.

Genetic Term Definition What does this mean? Other Common Terms Results from Penn Results from Laboklin

Homozygous Negative

A dog without any of the variant alleles

A dog that has no copies of the variant alleles is at the least risk of developing PLN

  • 0
  • 0/0
  • No copies
  • 'Normal'
  • 'Clear'
  • Homozygous


N/N (Clear)


A dog with one copy of the variant alleles

A dog with one copy of the variant allele is at medium risk of developing PLN

  • 1
  • 0/1
  • 'Carrier'
  • 1 Copy
  • Heterozygous


N/PLN (Carrier)

Homozygous Positive

A dog with two copies of the variant alleles

A dog with two copies of the variant alleles is at the highest risk of developing PLN, but this does not mean it will develop PLN

  • 2
  • Both copies
  • Homozygous for the PLN causative mutation


PLN/PLN (Affected)

Affected refers to both copies of the allele,

it does not mean the dog is currently, or will be affected with PLN


A message from Pam Mandeville: 13 October 2015

"Note that from Thursday, October 15th, Penn will no longer accept paper submissions or checks (cheques). If you do submit in that fashion, they will contact you and ask you to go to the website and enter information there."

Please now use the PennGen website at: and follow instructions to establish Your Account as requested in the August Update below.

Update from Pam Mandeville: August 2015

Hi all,

We wanted to give everyone a heads up about the change that is coming for those submitting samples for testing to Penn.

Starting in October, the test will be added to the PennGen website at  This site will allow you to provide all the information for your dog, print out a form to include with your swabs and then receive your results when complete.

The site will make certain things easier:

  • You'll establish your "account" once, when you are testing your first dog.  Then in the future, you just have to add the dog information.
  • You'll be able to check on whether your sample arrived at Penn...that way, you'll know who to follow up with.
  • You'll get an email when results are ready, pay on a secure site and your results will be available online.

Something that will excite our data-loving folks...Dr. Henthorn will be able to pull aggregate data easily so we'll know how things are going as a breed.

We know this is a change to what we've gotten used to.  When Dr. Henthorn is closer to being ready to go live, we'll do a sample dog and update our "Step By Step Guide" to ease the transition.

Stay tuned for more information...but if you have questions now, let me know and I'll get them answered.

Pam, DNA Marker Test Liaison

Submitting Test Swabs

It is VERY IMPORTANT that you follow the instructions guides on The SCWT Club of America's web page and that the two swabs and documents submitted for each dog are clearly identifiable with details for both owner and dog.

Remember to include credit card details on the submission form. Take copies of the documents you send for future reference.

A few points specific for UK participants:

1. Two swabs, associated paperwork and suitable 'bubble wrap' is about 50 gms and can be sent at letter rate.

2. Customs - items sent at 'Letter Rate' do not need a Customs Declaration, otherwise state: 'plastic brushes and stationery'

3. A four generation pedigree can be provided by WHI (via e-mail) if one is not available.

4. The Guidance notes suggest avoidance of weekend receipt of samples in the USA, but please note this refers only to blood samples that are sent and does not apply to swab tests.

5. The Guidance notes also refer to a Ziploc bag. To avoid confusion this is a clear plastic re-usable/re-sealable bag, generally used for sandwiches or fridge/freezer storage.

Test outcomes

You will be contacted direct with your dog's result. This is confidential between you and the Researchers.

Please remember that the genetic status of both sire and dam will influence their offspring.

Carefully read 'UNDERSTANDING BREEDING COMBINATIONS - A Breeders' Tool' (an update January 2014), click here for pdf.


If you have any questions contact the SCWTCA liaison Pam Mandeville at

Thank you for your participation.

What is PLN?

Further reading about PLN can be found on our pages about hereditary diseases.

1. primary information

2. comparisons with other hereditary diseases

3. help with diagnosis

Wheaten Health Initiative make a donation to PLN research

The WHI Genetic Research Fund is held with the object of providing assistance to research organisations involved in this important area of work. The Steering Group of WHI agreed that the PLN research project initiated by Drs Littman and Henthorn, should receive some of the money from this Fund.

On 15 May 2012, a donation of £532.90, just over $800 USD, was transacted through the aid of SCWTCA Endowment Inc., to Drs Meryl Littman and Paula Henthorn, of the University of Pennsylvania School of Veterinary Medicine in support of their recent research: Genetic Testing for PLN-Associated Variant Genes.

Read Dr Littman reply.