Decoding Genetic Testing- What are we testing for and why it matters!!!!

 Even if you aren't waiting for a KP puppy, please please PLEASE make sure to only buy from breeders who have gone through testing their breeding stock! This is a benchmark for a reputable breeder of any breed. All of the following information is from OFA and Pawprint Genetics- both of which are the premier sources for canine health testing!

Physical Clearances:
1)Hip Clearance via OFA
The OFA classifies hips into seven different categories: Excellent, Good, Fair (all within Normal limits), Borderline, and then Mild, Moderate, or Severe (the last three considered Dysplastic).
Excellent: Superior conformation; there is a deep-seated ball (femoral head) that fits tightly into a well-formed socketgood hips in dogs (acetabulum) with minimal joint space.
Good: Slightly less than superior but a well-formed congruent hip joint is visualized. The ball fits well into the socket and good coverage is present.
Fair: Minor irregularities; the hip joint is wider than a good hip. The ball slips slightly out of the socket. The socket may also appear slightly shallow.
Borderline: Not clear. Usually more incongruency present than what occurs in a fair but there are no arthritic changes present that definitively diagnose the hip joint being dysplastic.
Mild: Significant subluxationfair hips in dogs present where the ball is partially out of the socket causing an increased joint space. The socket is usually shallow only partially covering the ball.
Moderate: The ball is barely seated into a shallow socket. There are secondary arthritic bone changes usually along the femoral neck and head (remodeling), acetabular rim changes (osteophytes or bone spurs) and various degrees of trabecular bone pattern changes (sclerosis).
Severe: Marked evidence that hip dysplasia exists. The ball is partly or completely out of a shallow socket. Significant arthritic bone changes along the femoral neck and head and acetabular rim changesmild hip dysplasia in dogs.
--------------------------------------------------------------------------------
2) Eye Clearance via OFA
The procedure, which is conducted yearly, involves a careful and comprehensive examination of the eye. A dog's pupils, lens, cornea, retina, and in the anterior chamber are carefully examined.
There are currently ten disorders for which there is an unequivocal recommendation against breeding in all breeds. 
Keratoconjunctivitis sicca (KCS) – Breeding is not recommended for any animal demonstrating keratitis consistent with KCS. The prudent approach is to assume KCS to be hereditary except in cases suspected to be non-genetic in origin. See above note.
Cataract – Breeding is not recommended for any animal demonstrating partial or complete opacity of the lens or its capsule unless the examiner has also checked the space for “significance of above cataract unknown” or unless specified otherwise for the particular breed. See above note.
Lens luxation or subluxation – See above note.
Glaucoma – See above note.
Persistent hyperplastic primary vitreous (PHPV)
Retinal detachment – See above note.
Retinal dysplasia – geographic or detached forms – See above note.
Optic nerve coloboma
Optic nerve hypoplasia
Progressive Retinal Atrophy (PRA) – Breeding is not advised for any animal demonstrating bilaterally symmetric retinal degeneration (considered to be PRA unless proven otherwise).
--------------------------------------------------------------------------------
3) Heart Clearance via OFA
Congenital or advanced Cardiac Exam at 12 months or older, with exam by cardiologist.
Purpose: To identify dogs which are phenotypically normal prior to use in a breeding program. For the purposes of the registry, a phenotypically normal dog is defined as one without a cardiac murmur or one with an innocent heart murmur that is found to be otherwise normal by virtue of an echocardiographic examination which includes doppler studies.
Abnormal cardiac grades (1 is better, 6 is worst):
Grade 1: A very soft murmur only detected after very careful auscultation
Grade 2: A soft murmur that is readily evident
Grade 3: A moderately intense murmur not associated with a palpable precordial thrill (vibration)
Grade 4: A loud murmur; a palpable precordial thrill is not present or is intermittent
Grade 5: A loud cardiac murmur associated with a palpable precordial thrill; the murmur is not audible when the stethoscope is lifted from the thoracic body wall
Grade 6: A loud cardiac murmur associated with a palpable precordial thrill and audible even when the stethoscope is lifted from the thoracic wall
--------------------------------------------------------------------------------
4) Elbows via OFA
Elbow dysplasia is a general term used to identify an inherited disease in the elbow. Three specific variations seen: ulnar (FCP), elbow joint (OCD), anconeal (also ulnar)(UAP). 
Abnormal elbow grades (1 is better, 3 is worst). Grade of "Normal" denotes no disease noted on x-ray.
Grade I Elbow Dysplasia: Minimal bone change along anconeal process of ulna (less than 2mm). With careful consideration, may still be suitable for breeding programs.
Grade II Elbow Dysplasia: Additional bone proliferation along anconeal process (2-5 mm) and subchondral bone changes (trochlear notch sclerosis). Breeding at this point should be carefully scruitinized, generally avoiding breeding is best.
Grade III Elbow Dysplasia: Well developed degenerative joint disease with bone proliferation along anconeal process being greater than 5 mm. Should NOT be breeding.
Clinical signs involve lameness which may remain subtle for long periods of time. No one can predict at what age lameness will occur in a dog due to a large number of genetic and environmental factors such as degree of severity of changes, rate of weight gain, amount of exercise, etc.. Subtle changes in gait may be characterized by excessive inward deviation of the paw which raises the outside of the paw so that it receives less weight and distributes more mechanical weight on the outside (lateral) aspect of the elbow joint away from the lesions located on the inside of the joint. Range of motion in the elbow is also decreased.
--------------------------------------------------------------------------------
DNA Testing:
In addition to examination of the physical structures of a dog in a breeding progam, it is VERY important a potenial buyer see genetic testing results as well. There is a program known as CHIC that is a good sign to see in a dog- a dog achieves CHIC Certification if it has been screened for every disease recommended by the parent club for that breed and those results are publicly available in the database. 
There are 4 very distinct results for genetic testing: Normal (all clear!), Carrier (disease not active but if bred with another carrier offspring may be carriers or have active disease), At Risk (disease is present but genes are mutated- may or may not be active, mutated gene WILL be passed to offspring), and Equivocal (testing was inconclusive). 
1) Progressive Retinal Atrophy, Progressive Rod-Cone Degeneration (PRA-prcd)
Progressive retinal Atrophy, progressive Rod-cone degeneration (PRA-prcd) is a late onset, inherited eye disease affecting Golden Retrievers. PRA-prcd occurs as a result of degeneration of both rod and cone type Photoreceptor Cells of the Retina, which are important for vision in dim and bright light, respectively. Evidence of retinal disease in affected dogs can first be seen on exam around 1.5 years of age for most breeds, but most affected Golden Retrievers will not show signs of vision loss until 5 to 6 years of age or later. 
Affected dogs will initially have vision deficits in dim light (night blindness) and loss of peripheral vision. Over time affected dogs continue to lose night vision and begin to show visual deficits in bright light. Other signs of progressive retinal atrophy involve changes in reflectivity and appearance of a structure behind the retina called the Tapetum that can be observed on a veterinary eye exam. Although there is individual and breed variation in the age of onset and the rate of disease progression, the disease eventually progresses to complete blindness in most dogs. Other inherited disorders of the eye can appear similar to PRA-prcd. Genetic testing may help clarify if a dog is affected with PRA-prcd or another inherited condition of the eye.
--------------------------------------------------------------------------------
2) Progressive Retinal Atrophy, Golden Retriever 1 (PRA-1)
Progressive retinal Atrophy, golden retriever 1 (GR-PRA1) is a late-onset inherited eye disease affecting golden retrievers. Affected dogs begin showing clinical symptoms related to retinal degeneration between 6 to 7 years of age on average, though age of onset can vary. Initial clinical signs of progressive retinal atrophy involve changes in reflectivity and appearance of a structure behind the Retina called the Tapetum that can be observed on a veterinary eye exam. Progression of the disease leads to thinning of the retinal blood vessels, signifying decreased blood flow to the retina. Affected dogs initially have vision loss in dim light (night blindness) and loss of peripheral vision, eventually progressing to complete blindness in most affected dogs.
 Though the frequency in the overall golden retriever population is unknown, in one study of 369 golden retrievers clinically free of disease tested from the UK, US, Sweden, and France, 10.5% were carriers of the mutation.
--------------------------------------------------------------------------------
3) Progressive Retinal Atrophy, Golden Retriever 2 (PRA-2)
Progressive retinal Atrophy, golden retriever 2 (GR-PRA2) is the same disease as PRA-1, but with a different gene housing the mutation. Disease progression is the same, this mutation is less prevalent than PRA-1. 
Though the frequency in the overall golden retriever population is unknown, in one study of golden retrievers either free of clinical disease or of unknown PRA status tested from the UK, US, France, and Sweden, 3% were carriers of the mutation.
See information above.
--------------------------------------------------------------------------------
4) Ichthyosis status
Ichthyosis is an inherited condition of the skin affecting golden retrievers. The age of onset and severity of disease are highly variable, however most affected dogs present before one year of age with flaky skin and dull hair. Over time the skin develops a grayish color and appears thick and scaly, especially over the abdomen. The symptoms may progress to severe scaling all over the body, may improve with age, or may come and go over the dog’s lifetime. While the prognosis is generally good for affected dogs, they are at increased risk for skin infections. Though the exact frequency in the overall golden retriever population is unknown, approximately 44% out of 1600 golden retrievers tested from Australia, France, Switzerland, and the United States were carriers of the mutation and approximately 29% were affected.
--------------------------------------------------------------------------------
5) Degenerative Myelopathy
Degenerative Myelopathy is an inherited neurologic disorder of dogs. This mutation is found in many breeds of dog, including the golden retriever.  The variable presentation between breeds suggests that there are environmental or other genetic factors responsible for modifying disease expression. The average age of onset is approximately nine years of age. The disease affects the White Matter tissue of the spinal cord and is considered the canine equivalent to ALS (Lou Gehrig’s disease) found in humans. Affected dogs usually present in adulthood with gradual muscle Atrophy and loss of coordination typically beginning in the hind limbs due to degeneration of the nerves. The condition is not typically painful for the dog, but will progress until the dog is no longer able to walk. The gait of dogs affected with degenerative myelopathy can be difficult to distinguish from the gait of dogs with hip dysplasia, arthritis of other joints of the hind limbs, or intervertebral disc disease. Late in the progression of disease, dogs may lose fecal and urinary continence and the forelimbs may be affected. Affected dogs may fully lose the ability to walk 6 months to 2 years after the onset of symptoms. Affected medium to large breed dogs, such as the golden retriever, can be difficult to manage and owners often elect euthanasia when their dog can no longer support weight in the hind limbs.
--------------------------------------------------------------------------------
6) NCL (NEURONAL CEROID LIPOFUSCINOSIS)
The neuronal ceroid-lipofuscinoses (NCLs) are a class of inherited neurological disorders that have been diagnosed in dogs, humans, cats, sheep, goats, cynomolgus monkeys, cattle, horses, and lovebirds. Among dogs, NCL has been reported in many breeds, including English Setters, Tibetan Terriers, American Bulldogs, Dachshunds, Polish Lowland Sheepdogs, Border Collies, Dalmatians, Miniature Schnauzers, Australian Shepherds, Australian Cattle Dogs, Golden Retrievers, and other breeds. NCL is almost always inherited as an autosomal recessive trait.
All of the NCLs have two things in common: pathological degenerative changes occur in the central nervous system, and nerve cells accumulate material that is fluorescent when examined under blue or ultraviolet light. Although neurological signs are always present in canine NCL, these signs vary substantially between breeds and can overlap with signs present in other neurological disorders. Until the gene defect responsible for NCL has been identified for a particular breed, a definitive diagnosis can only be made upon microscopic examination of nervous tissues at necropsy. Fortunately DNA testing is available for Golden Retrievers.
In Golden Retrievers this neurologic disease becomes apparent at approximately 13 months of age.  Often the first sign of disease is a subtle loss of coordination that is more apparent when the dog is excited.   The extent of the incoordination gradually increases.  The dog may begin pacing or circling when 15 months old and seizures often start before 18 months of age.  Visual impairment and behavioral changes also start at that time.  The neurologic deficiencies slowly but relentlessly increase and affected Golden Retrievers are often euthanized due to deteriorating quality of life when 30-to-35 months old.