Breeds Affected: Dachshund
Samples Accepted: Blood, Buccal Swabs
Disease Information: NCL1 is a lysosomal storage disease with progressive neurodegeneration. Affected animals start to have retina changes around 7 months of age, which progresses quickly to severe vision loss or full blindness. By 9 months of age more symptoms are obvious, including weakness, trouble balancing, difficulty walking, a rounded back, and behaviour changes including nervousness and disorientation. There is no treatment for NCL1.
Inheritance Information: NCL1 is autosomal recessive, meaning that animals with two copies of this allele will be affected. Animals with one copy of the gene will be clinically-normal carriers.
The possible genotypes are:
N/N The dog is normal, and cannot produce affected offspring.
N/ncl1 The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/nlc1 carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
ncl1/ncl1 The dog is affected. If bred to a normal animal, 100% of the offspring will be carriers. If bred to an N/nlc1 carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/ncl1 x N/N) without any risk of producing affected offspring. The offspring should be tested before breeding to determine if they are carriers or normal.
– Breeding two carriers (N/ncl1 x N/ncl1) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (ncl1/ncl1) should not be used for breeding.
Test Information: This mutation test identifies a single base insertion in exon 8 of the PPT1 gene.
Sanders, DN., Farias, FH., Johnson, GS., Chiang, V., Cook, JR., O’Brien, DP., Hofmann, SL., Lu, JY., Katz, ML.: A mutation in canine PPT1 causes early onset neuronal ceroid lipofuscinosis in a Dachshund. Mol Genet Metab 100:349-56, 2010. Pubmed reference: 20494602. Doi: 10.1016/j.ymgme.2010.04.009.
Further information is available at the Online Mendelian Inheritance in Animals website.