UC Davis School of Veterinary Medicine Veterinary Genetics Laboratory
SERVICES

Italian Greyhound Genetic Tests

Autosomal Recessive Amelogenesis Imperfecta(ARAI) or Familial Enamel Hypoplasia of Italian Greyhounds

Introduction

Autosomal recessive amelogenesis imperfecta (ARAI) is an inherited genetic disorder of tooth enamel that occurs in Italian Greyhounds. It is commonly known to breeders as Familial Enamel Hypoplasia (FEH). It is characterized by enamel pitting and tooth discoloration; often teeth are unusually small, pointed and prone to increasing gaps between teeth with age. There appears to be no association of FEH with periodontitis. Dr. Niels Pedersen and his research group at the School of Veterinary Medicine, University of California-Davis identified the mutation associated with FEH in Italian Greyhounds.  It is estimated that 14% of Italian Greyhounds are affected with FEH and 30% are carriers.

Italian Greyhound with normal teeth. Teeth are larger, not pointed; enamel is smooth, not discolored. Gaps between teeth are narrower.

Italian Greyhound with FEH. The enamel surfaces are roughened, with blochy discoloration. Cavities are uncommon, but this dog has cavities at tips of upper and lower canines.

The Veterinary Genetics Laboratory offers a test for FEH to assist owners and breeders in identifying affected and carrier dogs. The test uses DNA collected from buccal (cheek) swabs, thus avoiding blood sample collection. Breeders can use results from the test as a tool for selection of mating pairs to avoid producing affected dogs.

Female

Male

N/N

N/FEH

FEH/FEH

N/N

100% N/N

50% N/N, 50% N/FEH

100% N/FEH

N/FEH

50% N/N, 50% N/FEH

25% N/N, 50% N/FEH, 25% FEH/FEH

50% N/FEH, 50% FEH/FEH

FEH/FEH

100% N/FEH

50% N/FEH, 50%FEH/FEH

100%FEH/FEH

ORDER TEST KITS | PRICE LIST
Allow 2-6 business days for results.

Results reported as:

N/N: no copies of FEH mutation; dog is normal
N/FEH: 1 copy of FEH mutation; dog is normal but is a carrier
FEH/FEH: 2 copies of FEH mutation; dog is affected.

 

Susceptibility to Primary Closed Angle Glaucoma in Italian Greyounds

Introduction

In Italian Greyhounds, primary closed angle glaucoma is a hereditary disease that results from a rapid build-up of pressure in the eye, which causes loss of optic nerve function and retinal ganglion cell loss. The onset of this condition is sudden, painful and if left untreated will lead to blindness. The average age of dogs at diagnosis is 3.9 years (range 0.5 to 6 years). Research by Dr. Niels Pedersen and Hongwei Liu at UC Davis identified 2 linked mutations that are present in 75% of Italian Greyhounds with primary closed angle glaucoma.

The VGL offers a test to allow owners to identify dogs at higher risk of this form of glaucoma, and to assist breeders to select breeding pairs to avoid producing offspring at higher risk.

ORDER TEST KITS | PRICE LIST
Allow 6-10 business days for results.

Results reported as:

N/N No copies of the glaucoma associated haplotype. Dog has a low risk (2%) of developing primary closed angle glaucoma.
N/S 1 copy of the glaucoma associated haplotype. Dog has a low risk (2%) of developing primary closed angle glaucoma.  Breedings between carriers are expected to produce 25% higher risk offspring.
S/S 2 copies of the glaucoma associated haplotype. Dog is 60 times more likely to develop primary closed angle glaucoma.

Note: this test is specific for the 2 mutations associated with susceptibility to primary closed angle glaucoma in the Italian Greyhound breed. This test is not valid for other breeds.

 

Susceptibility to PRA in Italian Greyounds

Introduction

Progressive retinal atrophy (PRA) is a genetic disease characterized by progressive degeneration of the photoreceptors in the retina that leads to blindness. There is no treatment for PRA. The incidence of PRA in Italian Greyhounds is 2-4% and it is usually diagnosed at 1 to 14 years of age (6.5 years average). Recent discoveries by UC Davis canine researchers Dr. Niels Pedersen and Hongwei Liu identified mutations in 5 loci that are associated with susceptibility to 90% of the PRA in Italian Greyhounds. This form of PRA, designated as PRA-IG1, can be subdivided into 3 subtypes (PRA-IG1a, 1b, and 1c) based on risk genotypes. PRA-IG1a is associated with allele (a) at the major locus that is solely responsible for blindness when in a homozygous state (aa).  PRA-IG1b occurs when this allele is in the heterozygous state (Aa) and associated with alleles b and c.  PRA-IG1c involves alleles a, d and e loci in various combinations.   PRA-IG1a comprises 42% of PRA cases in the breed, PRA-IG1b 29%, and PRA-IG1c 20%.  The frequency of the PRA-risk alleles in the general population is shown in the following table:

Frequency of the normal and PRA-risk alleles in healthy Italian Greyhounds

Locus

A

B

C

D

E

PRA-risk allele

12%

30%

19%

9%

25%

Normal allele

88%

70%

81%

91%

75%

Total dogs tested

300

299

300

146

142

Based on this research, IG are 30 times more likely to develop PRA-IG1 if they have either 2 copies of the mutation at the major locus (aa) or 2 copies of the mutation at minor locus D (dd). Italian Greyhounds are 9 times more likely if they have 1 copy of the mutation at the major locus and at least 1 copy of mutations at minor loci b and c (Aa/ b-/c- genotype). Italian greyhounds are 5 times more likely to develop PRA if they have 1 copy of the mutation at the major locus and at least 1 copy of mutations at minor loci d and e (Aa/ d-/e- genotype). Matings between dogs with AA genotype (and without “d” variant) will yield low risk offspring. Breeders should avoid mating any dogs that will produce puppies with PRA-susceptible genotypes.

VGL offers a test to identify Italian Greyhounds at higher risk of PRA-IG1 and assist breeders to select mating pairs that avoid producing puppies with higher risk to develop this form of PRA. This test can be used to confirm the diagnosis of this form of PRA.

ORDER TEST KITS | PRICE LIST
Allow 6-10 business days for results.

Examples of how results are reported:

Detailed report for PRA-IG1a status in Italian Greyhounds

Status

Risk factor

A

B

C

D

E

PRA-risk

30x

aa

--

--

--

--

PRA-risk

30x

aa

--

--

--

--

PRA-risk

30x

aa

--

--

--

--

PRA-risk

30x

aa

--

--

--

--

PRA-risk

30x

aa

--

--

--

--

PRA-risk

30x

aa

--

--

--

--

PRA-risk

30x

aa

--

--

--

--

PRA-risk

30x

aa

--

--

--

--

PRA-risk

30x

aa

--

--

--

--

             

Detailed report for PRA-IG1b status in Italian Greyhounds

Status

Risk factor

A

B

C

D

E

PRA-risk

9x

Aa

Bb

Cc

--

--

PRA-risk

9x

Aa

Bb

cc

--

--

PRA-risk

9x

Aa

bb

Cc

--

--

PRA-risk

9x

Aa

bb

cc

--

--

carrier

low

Aa

BB

CC

--

--

carrier

low

Aa

BB

Cc

--

--

carrier

low

Aa

BB

cc

--

--

carrier

low

Aa

Bb

CC

--

--

carrier

low

Aa

bb

CC

--

--

             

Normal

low

AA

BB

CC

--

--

Normal

low

AA

BB

Cc

--

--

Normal

low

AA

BB

cc

--

--

Normal

low

AA

Bb

CC

--

--

Normal

low

AA

Bb

Cc

--

--

Normal

low

AA

Bb

cc

--

--

Normal

low

AA

bb

CC

--

--

Normal

low

AA

bb

Cc

--

--

Normal

low

AA

bb

cc

--

--

             

Detailed report for PRA-IG1c status in Italian Greyhounds

Status

Risk factor

A

B

C

D

E

PRA-risk

30x

--

--

--

dd

--

PRA-risk

5x

Aa

--

--

Dd

Ee

PRA-risk

5x

Aa

--

--

Dd

ee

--

--

carrier

low

Aa

--

--

DD

EE

carrier

low

Aa

--

--

DD

Ee

carrier

low

Aa

--

--

DD

ee

carrier

low

Aa

--

--

Dd

EE

--

--

Normal

low

AA

--

--

DD

EE

Normal

low

AA

--

--

DD

Ee

Normal

low

AA

--

--

DD

ee

Normal

low

AA

--

--

Dd

EE

Normal

low

AA

--

--

Dd

Ee

Normal

low

AA

--

--

Dd

ee

Note: This test is specific for 5 mutations associated with susceptibility to the major cause of PRA presently occurring in the Italian Greyhound breed. This test is not valid for other breeds. It is important to note that there may be other genetic form(s) of PRA in the breedFurther research on IGs diagnosed with PRA that does not fit the genotype of PRA-IG1 will be required to identify additional causative mutation(s).

 
Veterinary Genetics Laboratory, Tel 530-752-2211, Email VGL