G-6-S FAQ’s

Prepared with input from the testing laboratory


What is the status of this test at ADGA?

The ADGA Board of Directors has approved including the laboratory results with the pedigree information upon breeder permission.  Use this request form if you want your results available with pedigree information (certificates, performance pedigrees, etc.). If you do not want to use the form, contact  performanceprograms@adga.org  directly or provide a signed statement with the registration IDs and the test type to make available along with your membership information.  Unregistered animals will need to be registered for this update to be applied.  Requests need to be made on a per individual animal basis.  

Current list of tested animals that have had breeder permission to make the information available.  Click HERE

Do I have to test?

No, this testing is voluntary.  There are no current plans to make this testing mandatory.

How do I order?

We have developed a website form for easy use.  To order, Go to https://adga.org/individual-dna-casein-g-6-s/ and click on order form.  We then send the materials and instructions for sampling and mailing to you.

I’ve already had my animal tested for identity or casein.  What are my options?

For most samples at the lab, it is possible to just request the test without additional sampling.  If the lab has exhausted the material with other testing, they will let us know and you would need to re-sample and submit.  We would generate new submission materials in this case and send to you.  Also, if you request G6S testing and want to add tests later, the same process applies.

How is payment handled?

Payment needs to be made prior to materials being generated.  You can add funds to your account, call in credit card information, or send by regular mail.  Once the funds are in place, we generate the materials for the samples.  This includes instructions for sampling and mailing.

What Sample Types are acceptable?

The lab prefers hair although blood and semen can be used as well.  Hair roots have been validated as a robust source of DNA for PCR-based genetic testing in many species. The scientific literature is rich with examples where DNA was sourced from hair roots.  Millions of DNA genotypes have been produced in this way for domestic animals since DNA testing began in mid-late 1990’s. For this type of testing, hair samples are just as accurate as blood or semen.

How are results provided?

If you have a valid email address on file with ADGA the results, which are pdf files generated by the lab, can be forwarded to you.  Otherwise, they will be mailed to you. 

How are results reported?

G6S DNA profiles are reported as N/N for normal, N/G for carrier and G/G for affected goats.  This information is stored in the ADGA database.

What makes a DNA test robust for routine use?

A combination of sufficient amount of DNA, good optimization of the PCR reaction for highly specific amplification of target DNA sequences, good laboratory quality controls to avoid cross-contamination of samples and reagents, and the use of appropriate references for every assay that act as indicators that tests are working as expected. All these requirements are in place for tests performed by the Veterinary Genetics Laboratory.

How accurate is the test?

The assay itself yields very clear, unambiguous profiles. Test accuracy for the VGL test is effectively 100% because of duplicate testing of independent DNA extractions for each animal, with a result matching requirement before reports are issued.  This accuracy does not depend on the type of sample that is submitted.

Why is there a disclaimer on the submission form?

ADGA allows members to provide their own sampling rather than require a third party to collect the samples (required in some registries) in response to the membership wanting to keep DNA testing cost effective.   ADGA relies on membership integrity in all areas.  This disclaimer allows for that process.

How is VGL accredited?

Laboratories engaged in animal DNA testing follow procedures that are very similar to those used by human laboratories in terms of quality controls for PCR tests. VGL has several accreditations, such as ISO17025 and ASCLD/LAB – International which requires meeting strict standards.  Also, the International Society for Animal Genetics (ISAG) recognizes the parentage tests offered by VGL as meeting international standards. The laboratory takes part in the biannual horse, cattle, sheep/goat, cat and dog parentage comparison tests carried out under their auspices. 

Will results from other labs be accepted?

ADGA has followed a policy of accepting results from other labs if the testing is the same, if it comes directly from the lab and if information is in place with regard to animal identification.  This entails having a registration number on the lab results.  If unregistered, the information needs to include tattoo, date of birth, breed and gender.  This allows us to update the database once the animal is registered as long as the information correlates.


Clavijo, A., F. Sun, L. Sneed (2010) Diagnosis of caprine mucopolysaccharidosis type IIID by real-time polymerase chain reaction-based genotyping. Journal of Veterinary Diagnostic Investigation 22:622-627. http://vdi.sagepub.com/content/22/4/622.long


Siriwat Wasiksiri, Sirichai Sripongpun, Adisorn Ratanaphan, Panom Sookras, A Survey to Determine the Presence of the N-acetylglucosamine-6-sulfatase (G6S) Gene Mutation in Anglo-Nubian Goats in Southern Thailand, Thai J Vet Med. 2013. 43(1): 99-103. http://www.tci-thaijo.org/index.php/tjvm/article/view/9542


Hoard, H.M. et al. (1998) Determination of genotypic frequency of caprine mucopolysaccharidosis IIID. Journal of Veterinary Diagnostic Investigation 10: 181-183 http://vdi.sagepub.com/content/10/2/181.full.pdf


Karen Friderici et al, Cloning and sequence analysis of caprine N-acetylglucosamine 6-sulfatase cDNA, Biochimica et Biophysica Acta (BBA) – Molecular Basis of Disease Volume 1271, Issues 2–3, 9 June 1995, Pages 369–373 http://www.sciencedirect.com/science/article/pii/0925443995000548


Thompson, J. N., Jones, M. Z., Dawson, G., Huffman, P. S. N-acetylglucosamine 6-sulphatase deficiency in a Nubian goat: a model of Sanfilippo syndrome type D (mucopolysaccharidosis IIID). J. Inherit. Metab. Dis. 15: 760-768, 1992.  http://www.ncbi.nlm.nih.gov/pubmed/1434515   https://books.google.com/books?id=RJS9NEpYnd8C&pg=PT372&lpg=PT372&dq=-acetylglucosamine+6-sulphatase+deficiency+in+a+Nubian+goat:+a+model+of+Sanfilippo+syndrome&source=bl&ots=JN6nzveiAx&sig=VKd1CCq0oO8oZUaGiHuo-8wlDr4&hl=en&sa=X&ved=0CB8Q6AEwAGoVChMI4caIodeiyAIVRRYeCh2NKQvn#v=onepage&q=-acetylglucosamine%206-sulphatase%20deficiency%20in%20a%20Nubian%20goat%3A%20a%20model%20of%20Sanfilippo%20syndrome&f=false