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GLYCOGEN STORAGE DISEASE TYPE 4
A Sad Story.
All results have come back from the Lab and it's such good news for not only our breeding but also all our future plans - we are now a GSDIV free cattery :-)
As some of you already know we have had a sad situation going on here in the Landsker Household. On the 26th of June this year we received an email from Lysander's breeder in Germany telling us that his sister had been found to carry a copy of the Glycogen Storage Disease type 4. I had mistakenly thought that his parents were tested negative and so was rather shocked at this turn of events. Needless to say we sent off swabs straight away and awaited the results. For whatever reason it took almost 3 weeks for the results to come back and they came back positive for one copy of the gene and we were truly heartbroken as Lysander is such a wonderful boy with a lovely disposition and type. Lysander was neutered the following week and I emailed his breeder to tell her so and to ask why his parents weren't tested, fortunately now his breeder has decided to test Lysander's mother at least and she has come back positive for the gene and you can find her pedigree information below. Lysander's father remains untested.
We then swabbed all his kittens and sent off the samples to a different lab in the hopes that we would get the results a bit quicker, unfortunately fortune wasn't on our side and some of the tests were inconclusive due to a lack of genetic material and we weren't that surprised because it's not easy to fit a swab into a kitten's mouth and make sure that you get enough cells to extract the DNA. So after only getting 6 results back out of the 9 we had a decision to make....do we blood test the kittens or just do the parents to make sure that only one copy of the gene could be passed on by their father. Some kitten owners were very worried that if they didn't have a test result that their kitten would go on to produce clinical signs of the disease and die so we knew that we had no choice but to test all parents of the kittens and therefore the best way would be to make sure that all our lines were free of it. You can see results of our tests below showing the name of the cat and the parents of the cat and we will be updating these as we receive the results from the laboratory.
It needs to be said that if you are going to have a lethal gene then this one as a simple autosomal recessive is one of the better ones to have as it is easily taken out of the breeding program by neutering all cats with a copy, thereby freeing the lines of any further heartache and as long as any cats then brought in to the cattery are tested free of the gene the lines remain clean. From now on all cats coming in for mating and all kittens that we buy from other breeders will be tested for this gene so that we will always be able to reassure people that our lines are free of it. You can find the write up of the GSD IV below, which can be found on the FAB site. As you can see there has been information about this disease since the latter part of the 1990's. Basically in lay persons terms you need to have both parents carrying a copy of the gene to have kittens go on to have the disease. One copy of the gene does not in any way affect the cat but if bred from it can pass the gene on as our results below show. Some breeders have said that they won't test because a kitten with only one copy can always be sold as a pet, in my view this is a mistake as if you don't test the parents there is always the risk that at some point you will sell on a pet kitten that may die when it's older and it's such a horrible death and totally unfair to the new owners so I'm hoping that as breeders start to understand more about this disease that they will see the need to test all their breeding cats so that prospective kitten buyers can rest assured that the kitten they buy is free of it.
Landsker Nimbus (Stud) - Landsker Ziegfeld Folly x Koeni's Lysander Swabs taken- GSD IV negative
Landsker Orrick - Dayjoy Helena x Koeni's Lysander Swabs taken - GSD IV 1 copy of the gene found
Landsker Parmida - Dayjoy Helena x Koeni's Lysander Swabs taken - GSD IV 1 copy of the gene found
Landsker Orianna - Dayjoy Helena x Koeni's Lysander Swabs taken - GSD IV negative
Landsker Oona Cajsa - Dayjoy Helena x Koeni's Lysander Swabs taken - GSD IV negative
Landsker Okalani - Dayjoy Helena x Koeni's Lysander Swabs taken - GSD IV negative
Alvenkatt Startrooper - Landsker Kisa x Jago vom Alpenwichtel Bloods taken - GSD IV negative
Landsker Nefertiti - Landsker Ziegfeld Folly x Lysander Bloods taken - GSD IV negative
S*Tigressan's Tippo - Gomorran's Blueshine x Gomorran's Totmes Bloods taken - GSD IV negative
Dayjoy Helena - Dayjoy Hermia x Eid av Isblomst Bloods taken - GSD IV negative
Norskmagi Lechsinska - Coscathas Pru x Landsker Neo Bloods taken - GSD IV negative
Merlynmajic Arwen - Landsker Fallon x S*Tigressan's Tippo Bloods taken - GSD IV negative
PL*Dune Duma Wikinga - Chacolis Aphrael x DK*La Forêt's Lescaux Bloods taken - GSD IV negative
Landsker Jamuna (Breeding queen in Hong Kong) Adcinlo Merlynmajic Arwen x Koeni's Lysander Tested in Hong Kong - GSD IV negative
Landsker Safari - Dayjoy Helena x Alvenkatt Star Trooper parents tested negative
Landsker Beau Baird parents negative
Landsker Yepa Yettie parents tested negative
Koeni's Curtis - Koeni's Pamina x S*Ambient Paul parents tested negative
FAB site states:
Glycogenosis (glycogen storage disease type IV)
Glycogen storage disease type IV of the Norwegian forest cat is an inherited abnormality of glucose metabolism. It is inherited as a simple autosomal recessive trait and can present in 2 types. By far the most common form is stillbirth or death within a few hours of birth. This probably results from the kittens having insufficient glucose to produce energy during the birth process and the first hours of life. On rare occasions, an affected kitten will survive the neonatal period and appear normal until 5 months of age. Though less common, this is the more devastating form of the disease because by this age new owners are attached to their kitten, and have to watch it go through months of neuromuscular degeneration. By 8 months of age, affected kittens have severe muscular weakness, atrophy and contractures, and inability to use their limbs. Affected cats may die suddenly from heart failure.
A DNA test is available for the diagnosis of affected kittens and the detection of carrier cats:
We used two Laboratories for our tests and found the results much quicker with the Pals lab than the Laboklin but both labs provide both the swab and blood tests for this gene
Coates J R et al (1996) A case presentation and discussion of type IV glycogen storage disease in a Norwegian forest cat. Progress in Veterinary Neurology 7, 5-11
Fyfe JC et al (1992) Glycogen Storage Disease Type-IV - Inherited Deficiency of Branching Enzyme Activity in Cats. Pediatric Research 32:719-725.
Gashen F et al (2004) Congential diseases of feline muscle and neuromuscular junction. Journal of Feline Medicine and Surgery 6, 355 - 366