NCL with the American Bulldog.

A collaboration of scientists from the Veterinary Neurological Center in Los Vegas, the University of Missouri-Columbia (UMC), the University of California-San Diego, and Cornell University in Ithaca has recently described a new form of NCL in American Bulldogs. At UMC we have been studying DNA from affected American Bulldogs and their relatives, and have discovered the mutation causing NCL in this breed. A DNA test is now available which will definitively identify clear, carrier, and affected dogs. The charge for this test is $40 per dog, payable to "University of Missouri". Instructions and forms for sending samples are found in the SAMPLE SUBMISSION section.
NCL Description for American Bulldogs
Age of onset of clinical signs: 0.9 to 3 years

Age of death or euthanasia: 3.5 to 5.5 years

Abnormalities often observed by the owner:
Mental changes: Physical symptoms may appear to worsen during times of stress. Affected dogs do not indicate they are in any pain as coordination decreases.
Changes in gait and posture: Initially, uncoordinated movement in the rear is noted. As the disease progresses, affected dogs develop a wide-based stance starting in rear, and eventually involving all four legs. Affected dogs may exhibit muscle twitching, especially when sleeping. The dogs remain well-muscled through the course of the disease.
Visual abnormalities: None reported
Seizures/convulsions: None reported
Other changes: None reported

Abnormalities observed upon clinical examinations:
Clinical neurologic changes: Progressive ataxia and hypermetria is present in all four limbs, but more pronounced in the pelvic limbs. Conscious proprioception and hopping reactions are delayed in the pelvic limbs but normal in the forelimbs on initial examination. In advanced stages conscious proprioception reactions are absent in all four limbs and dogs have difficulty rising from a recumbent position without assistance. A wide-based stance of the pelvic limbs is observed in younger affected dogs; this progresses to a wide-based stance of all four limbs at later examinations. Spinal reflexes and cranial nerve examinations are normal. The dogs remain well muscled.
Clinical ophthalmic changes: None reported
Visual abnormalities: None reported
Retinal changes: None reported
Electroretinography (ERG): None reported
Other clinical findings: None reported


Histopathology
Brain: The entire external surface of the brain has a light brown hue but there is no evidence of cortical atrophy. Microscopically, PAS-positive storage material is present in cerebral cortex, brainstem, and cerebellum. The storage material in all cells exhibits a golden-yellow autofluorescence. Axonal spheroids are present in the brain and spinal cord. Ultrastructurally, storage bodies consist of membrane-bound organelles with cross-sectional diameters generally ranging from 0.5 to 3 microns. The inclusion body profiles are sometimes round but more often irregular. The bulk of the storage body contents are coarsely granular and most storage bodies contain numbers of somewhat spherical aggregates of the granular material. In addition, storage bodies from all 3 cell types contain well-delineated spherical dark-staining inclusions that are mostly smaller than 0.1 microns in diameter. In some cells in and near the Purkinje cell layer of the cerebellum, the perinuclear cytoplasm is filled with storage material that appears to be an aggregation of smaller storage bodies that have fused.
Eyes: Microscopically, PAS-positive storage material is present in ganglion cells of the retina. Under electron microscopic examination, the storage bodies in retinal ganglion cells have an additional ultrastructural feature of lighter-staining spherical inclusions with the relatively uniform electron density typical of lipid droplets.
Other organs and structures: None noted

Mode of inheritance: Autosomal recessive.

Gene containing mutation: The causative mutation has been identified and a DNA test is now available. See details above.

References:
Evans J, Katz ML, Levesque D, Shelton D, deLahunta A and O’Brien DP: A Variant Form of Neuronal Ceroid Lipofuscinosis in American Bulldogs (2005) J. Vet. Internal Med., 19:44-51.

Hi jesper that is Great news

jorgen

NCL TESTING
Below are the NCL Testing Definitions and Breeding Risk Guidelines:




TEST RESULT DEFINITIONS:

CLEAR

This finding indicates that the gene is not present in your dog.

Therefore, when used for breeding,

a Clear dog will not pass on the disease gene.


CARRIER

This finding indicates that one copy of the disease gene is present in your dog,

but that it will not exhibit disease symptoms.

Carriers will not have medical problems as a result.

Dogs with Carrier status can be enjoyed without the fear of

developing medical problems but will pass on the disease gene 50% of the time.


AFFECTED

This finding indicates that two copies of the disease gene are present in the dog.

Unfortunately, the dog will be medically affected by the disease.

Appropriate treatment should be pursued by consulting a veterinarian.


BREEDING RISKS:

CLEAR X CLEAR = 100% CLEAR
Ideal Breeding Pair. Puppies will not have the disease gene

(neither as Carrier nor as Affected).



CLEAR X CARRIER = 50% CLEAR 50% CARRIER
Breeding Is Safe. No Affected puppies will be produced. However,

some of the puppies will be Carriers.
Accordingly, it is recommended that Carrier dogs

which are desirable for breeding be bred with Clear dogs in the future,

which will produce 50% carrier and 50% clear animals,

to further reduce the disease gene frequency.
These offspring should be tested for this defective gene,

and if possible, only the clear animals in this generation should be used



CARRIER X CARRIER = 25% CLEAR 50% CARRIER 25% AFFECTED
High Risk Breeding. Some puppies are likely to be Carriers

and some puppies are likely to be Affected.

Even though it is possible that there will be some clear puppies when

breeding "Carrier to Carrier", in general,

neither this type of breeding pair nor

"Carrier to Affected" are recommended for breeding.



CARRIER X AFFECTED = 50% CARRIER 50% AFFECTED
Breeding Not Recommended. -

All puppies will be genetically and medically affected



AFFECTED X AFFECTED = 100% AFFECTED
Breeding Not Recommended. -

All puppies will be medically affected






Bluebloods American Bulldogs - 2005