Canine Genetics Progress Report

Breed: Norwich Terrier

Condition: Epileptoid Cramping Syndrome

Date: 01.06.2009

Recent / Current Funding:

The project is currently being funded, in part, by the LUPA project
( ), of which the AHT is a participant, and by donations from individuals.

The AHT is studying the genetics of an epileptoid cramping condition in this breed, in the hope of identifying the mutation(s) responsible.

Sample Collection

Sample Collection has been progressing very well. We have collected samples from 230 Norwich Terriers, of which around 50 are reported by their owners or their vets to suffer from ‘epilepsy' or ‘cramps'. We continue to collect samples from affected dogs and their close relatives. The affected dogs we have collected so far are all relatively closely related to one another, and all descend from a single founding dog within 5 or 6 generations, which is indicative of an inherited condition.

( For Sample Submission Form please click here.
All forms and samples which are submitted to the Animal Health Trust remain with them as confidential information. The Norwich Terrier Club does not have access to that information.
To obtain buccal swab kits please contact)

Additional Information Needed

Discussions with neurology colleagues at the AHT revealed that epilepsy/cramping in the Norwich Terrier is quite poorly defined, from a clinical perspective, and our chances of eventually identifying the mutation responsible for the condition will be greatly enhanced if we can obtain a better clinical description of the condition.

To try and find out more about the condition we devised a questionnaire that we sent out to the owners of 43 affected dogs, asking for details about their dog's condition. We got replies back from the owners of 25, which has helped us understand a little bit more about this condition. We also asked the owners of all the dogs for which we have samples stored to update us on the clinical status of their dogs, for which we received 119 updates. If any owners have still to return their questionnaires, or to update us on the health status of their dogs please do so as soon as possible. If anybody would like another copy of the questionnaire please email to request a replacement. Knowing the type of condition we are studying helps us predict the type of genes that might be involved which could significantly expedite mutation discovery.

To continue to help us find out more about epilepsy/cramping in the Norwich Terrier there are two more things that would be very helpful:

•  Video clips of affected dogs while they are experiencing a ‘fit' or a ‘cramp attack'.

•  Better clinical information about the affected dogs for which we currently have samples and also any ‘new' cases we collect. Ideally, affected dogs would have a full neurological work-up, to eliminate other causes of the seizures/attacks. Dogs can experience seizures for many reasons, and only once all possible causes have been eliminated can a dog truly be diagnosed as having idiopathic epilepsy. We understand full work-ups of this nature are expensive, but the more information we can gather regarding which tests affected dogs have and haven't had, and the results of those tests, is very helpful. The owners of affected dogs whose samples are held at the AHT are encouraged to contact us if they think they have any information that wasn't submitted along with the original sample that might be useful, or additional information that might have developed since the samples was submitted. It is also very important the AHT is informed if any dogs develop epilepsy / cramps after their sample was submitted.

Progress to Date

The AHT is part of a European consortium (the so-called LUPA project; ) that is investigating several conditions (including epilepsy) that affect both humans and dogs. As part of the LUPA project the AHT has been able to access funds, and also samples owned by collaborative partners at the University of Helsinki, Finland, to begin research to identify the mutation(s) responsible for epilepsy/cramping in the Norwich Terrier.

We have undertaken a Whole Genome Scan (WGS) with samples from 38 affected and 38 unaffected Norwich Terriers. A WGS involves comparing 49,663 DNA markers from the DNA of affected and unaffected dogs to find regions of the genome that are shared between affected dogs and different in unaffected dogs. This is the first step to finding the mutations that are associated with the condition. The very exciting news is that we have identified at least three regions of the canine genome that seem to be associated with epilepsy/cramping and we are in the process of following up those regions now.

Coat Colour in the Norwich Terrier

As an aside to our studies into epilepsy/cramping we have also identified two genes that control coat colour in the Norwich Terrier. By undertaking some additional minor experiments it might be possible to develop a DNA test for coat colour, that would enable breeders to determine whether their Red dogs carried the Black & Tan allele (B & T is recessive to Red). It s normally not the policy of the Canine Genetics team at the AHT to develop DNA tests for cosmetic traits (such as coat colour) but would be prepared to consider doing so if the availability of such a test had wider health and welfare implications. For example, this might be the case if one particular colour was more desirable than another, causing breeders to avoid breeding with dogs that carried, or possibly carried, the less desirable coat colour gene. Offering a DNA test would enable breeders to breed with their ‘carriers', thus allowing more dogs to contribute to the gene pool of the breed. We would be interested to hear breeders opinion on this matter and invite them to email their comments to in the strictest confidence.

To return to the current progress report
( December 2009) - click here

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