DNA General Information

DNA testing based on identification of a specific gene mutation is 100% accurate for identification of animals that are clear of the disease (homozygous normal), carriers of the disease (phenotypically normal but heterozygous for normal and mutant alleles), or affected with the disease (homozygous for mutant alleles). Knowledge of the genotypic status is the breeder’s most powerful tool for elimination of a genetic disease.

Breeding of genetically clear individuals will produce offspring that are all genetically and phenotypically normal. Breedings of a clear with a carrier will produce all phenotypically normal offspring but 50% of the offspring are expected to be genotypic carriers. In the rare incidence where desirable traits of an affected individual outweigh the undesirable genetic trait, an affected individual may be bred to a clear and the offspring will be all phenotypically normal but genotypic carriers and these offspring should later be bred only with clear individuals. With careful breeding decision strategies, a number of excellent traits can be retained without offspring physically showing the genetic disease. DNA testing by linkage is not as accurate as that for identification of a specific gene mutation but it is still more desirable than existing tests based on phenotypic evaluations.

The financial advantages of DNA testing and associated DNA profiling are clear. The test is accurate, can be done at an early age, only one test is required and progeny can be cleared by parentage if DNA profiles are available for determination of parentage.

Diseases Diagnosed by DNA Tests

CLAD (Canine Leukocyte Adhesion Deficiency)
Technically known as Canine Leukocyte Adhesion Deficiency, this rare but devastating condition is an  inherited fatal immunodeficiency disease. For more information, go to the CLAD section of the Optigen website.

Canine Multi-focal Retinopathy (CMR)
CMR is a recently identified recessively inherited eye disease known so far to affect the Mastiffs (English, Bullmastiff, French mastiff or Dogue de Bordeaux), Great Pyrenees and Coton de Tulear. For more information, go to the CMR section of the Optigen website.

Centro Nuclear Myopathy (CNM)
Centronuclear Myopathy is a serious disease that has been seen in Labrador Retrievers globally since the 1970’s. For more information, go to the Alfort School of Medicine site.

Cobalamin Malabsorption

Collie Eye Anomaly (CEA)
For more information on CEA, go to the CEA section of the Optigen website.

Cone Degeneration
For more information on Cone Degeneration, go to the Optigen website.

Congenital Stationary Night Blindness
Also known as hereditary retinal dystrophy. A poorly understood condition in which nonprogressive night blindness is apparent by 5 to 6 weeks of age. There is currently no treatment.

Congenital Hypothyroidism with Goiter (CHG) (Toy Fox Terrier)

Copper Toxicosis
A genetic disorder that affects several breeds and causes copper accumulation in the body which leads to liver disease. It is estimated that 25% of Bedlington Terriers are affected by the disease and 50% are carriers at this time.

Cystinuria
An inherited disorder which is characterized by stone formation in the urinary tract. For more information, go to the Cystinuria section of the PennGen site.

Factor VII Deficiency
A hereditary bleeding disorder. For more information, go to the Factor VII section of the PennGen site.

Fucosidosis
Fucosidosis is a hereditary disease that occurs when a dog has a mutation in a gene that codes for the enzyme alpha-fucosidase. For more information, go to the Fucosidosis section of the PennGen site.

Glanzmann’s Thombasthenia (Otterhound)

Globoid Cell Leukodystrophy (GCL)
GCL is a fatal, autosomal recessive disease caused by mutations in the galactocerebrosidase (GALC) gene in Cairn and West Highland White Terriers.

Gray Collie Syndrome (Canine Cyclic Neutropenia)
Canine Cyclic Neutropenia is a stem cell disorder that occurs in gray collies. Puppies are usually smaller and weaker than their littermates and by 8 to 12 weeks of age they develop clinical signs such as fever, diarrhea, joint pain, or other signs associated with eye, respiratory, or skin infections.

Hyperparathyroidism
Primary Hyperparathyroidism (PHPT) is thought to be the second most common cause of pathologic hypercalcemia (increased serum calcium) in dogs. It is caused by an inappropriate secretion of parathyroid hormone (PTH) by autonomously functioning "chief" cells within the parathyroid glands in the neck of the dogs.

Juvenile Cataracts

MDR1 (multiple drug resistance)
Some breeds of dogs are more sensitive to certain drugs compared to other breeds. For example, Collies, Australian Shepherds and several other breeds are often more sensitive to the antiparasitic drug, ivermectin. For more information, go to the MDR1 section on Washington State University's Veterinary Clinical Pharmacology Lab.

MPS IIIB
Mucopolysaccharidoses (MPS) are a group of lysosomal storage disorders due to defects in the degradation of certain polysaccharides that are found surrounding cells in the tissues. For more information, go to the MPS section of the PennGen site.

MPS VI
Mucopolysaccharidoses (MPS) are a group of lysosomal storage disorders due to defects in the degradation of certain polysaccharides that are found surrounding cells in the tissues. For more information, go to the MPS section of the PennGen site.

MPS VII
Mucopolysaccharidoses (MPS) are a group of lysosomal storage disorders due to defects in the degradation of certain polysaccharides that are found surrounding cells in the tissues. For more information, go to the MPS section of the PennGen site.

Narcolepsy
Narcolepsy information can be found on the Optigen website.

Neonatal Encephalopathy

Neuronal Ceroid Lipofuscinosis

Phosphofructokinase Deficiency
A genetic deficiency which causes mild to moderate anemia with severe episodes of bleeding. For more information, see the PFK section of the PennGen site.

Progressive Retinal Atrophy
An inherited degenerative eye disorder that leads to blindness.

Pyruvate Kinase Deficiency
This is an enzyme that is normally found in red blood cells. When the levels of this enzyme are deficient, the blood cells break down prematurely. This causes the dog to become anemic, exhibit a lack of energy, and low exercise tolerance. For more information, see the PK section of the PennGen site.

Renal Dysplasia
More information about Renal Dysplasia can be found on the VetGen website.

Thrombopathia

von Willebrand's Disease
An inherited disease that leaves dogs susceptible to abnormal bleeding following injuries or surgical procedures.

DNA Laboratories include VetGen, Optigen, PennGen, HealthGene, Washington State University Veterinary Clinical Pharmacology Lab, and Dr. David Wenger

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