Table 5. Screening of the RPGRIP1 insertion in non-MLHD breeds.
| Breed |
RPGR1P1 genotype |
Breed |
RPGR1P1 genotype |
||||
|---|---|---|---|---|---|---|---|
| +/+ | +/− | −/− | +/+ | +/− | −/− | ||
| Beagle |
41 |
32 (+/−L) |
6 (-L/-L) |
Italian Greyhound |
1 |
0 |
0 |
| English Springer Spaniel |
27 |
35 |
7 |
Jack Russel Terrier |
9 |
0 |
0 |
| Labrador Retriever |
15 |
1 |
0 |
Kooiker Hondje |
1 |
0 |
0 |
| French Bulldog |
9 |
3 |
0 |
Lapponian Herder |
8 |
0 |
0 |
| Akita |
1 |
0 |
0 |
Leonberger |
1 |
0 |
0 |
| Alaskan Malamute |
1 |
0 |
0 |
Lhasa Apso |
18 |
0 |
0 |
| Australian Cattle Dog |
1 |
0 |
0 |
Lurcher |
7 |
0 |
0 |
| Basset Hound |
8 |
0 |
0 |
Maltese |
2 |
0 |
0 |
| Belgian Shepherd Malinois |
1 |
0 |
0 |
Miniature Pinscher |
1 |
0 |
0 |
| Bernese Mountain Dog |
7 |
0 |
0 |
Miniature Schnauzer |
8 |
0 |
0 |
| Bichon Frise |
8 |
0 |
0 |
Newfoundland |
8 |
0 |
0 |
| Border Collie |
7 |
0 |
0 |
New Zealand Hantaway |
1 |
0 |
0 |
| Borzoi |
1 |
0 |
0 |
Pomeranian |
1 |
0 |
0 |
| Boxer |
9 |
0 |
0 |
Poodle |
7 |
0 |
0 |
| Bull Terrier |
1 |
0 |
0 |
Pug |
3 |
0 |
0 |
| Cairn Terrier |
6 |
0 |
0 |
Rhodesian Ridgeback |
8 |
0 |
0 |
| Cardigan Welsh Corgi |
8 |
0 |
0 |
Rottweiler |
5 |
0 |
0 |
| Cavalier King Charles Spaniel |
11 |
0 |
0 |
Samoyed |
1 |
0 |
0 |
| Chihuahua |
1 |
0 |
0 |
Schipperke |
1 |
0 |
0 |
| Cocker Spaniel |
10 |
0 |
0 |
Shetland Sheep Dog |
2 |
0 |
0 |
| Collie Smooth/Rough |
8 |
0 |
0 |
Shiba Inu |
1 |
0 |
0 |
| Dachshund |
7 |
0 |
0 |
Shih Tzu |
8 |
0 |
0 |
| Dalmatian |
7 |
0 |
0 |
Siberian Husky |
1 |
0 |
0 |
| Doberman |
7 |
0 |
0 |
Saint Bernard |
1 |
0 |
0 |
| Finnish Lapphund |
6 |
0 |
0 |
Staffordshire Bull Terrier |
10 |
0 |
0 |
| Flatcoated Retriever |
9 |
0 |
0 |
Swedish Lapphund |
7 |
0 |
0 |
| German Shepherd Dog |
6 |
0 |
0 |
Toy Poodle |
2 |
0 |
0 |
| Golden Retreiver |
16 |
0 |
0 |
Weimaraner |
8 |
0 |
0 |
| Great Dane |
8 |
0 |
0 |
Welsh Corgi Pembroke |
2 |
0 |
0 |
| Great Pyrenees |
1 |
0 |
0 |
West Highland White Terrier |
7 |
0 |
0 |
| Greyhound |
8 |
0 |
0 |
Whippet |
7 |
0 |
0 |
| Hungarian Vizsla |
7 |
0 |
0 |
Wire Fox Terrier |
1 |
0 |
0 |
| Irish Setter |
8 |
0 |
0 |
Yorkshire Terrier |
7 |
0 |
0 |
| Total | 426 | 71 | 13 | ||||
Of the 66 dog breeds screened, the insertion was observed in the four breeds shown at the top. RPGRIP1 genotypes are denoted as follows: wildtype homozygote (+/+); heterozygote (+/−); insertion homozygote (−/−). The insertion allele (-L) in the Beagle had a longer polyA tract than the allele in the other breeds (see Figure 6). Of the four breeds with the insertion, homozygous individuals were found only among Beagles and English Springer Spaniels. Beagles that were RPGRIP1-L/-L showed no apparent visual dysfunction, but photopic ERG was undetectable. Some of the English Springer Spaniels were PRA-affected, and the three possible genotypes were found among these cases.