Breeds Affected: Giant Schnauzer
Samples Accepted: Blood, Buccal Swabs
Disease Information: Fetal-onset neuroaxonal dystrophy (FNAD) is a fatal disease in which parts of the central nervous system do not develop properly. Affected pups die shortly after birth from respiratory failure.
Inheritance Information: FNAD 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/fnad The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/fnad carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
fnad/fnad The dog is affected.
– Carriers may be bred to normal animals (N/fnad 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/fnad x N/fnad) is not recommended due to the possibility of 25% of the offspring being affected.
Test Information: This mutation test identifies an 3 base deletion in exon 14 of the MFN2 gene.
Fyfe, J.C., Al-Tamimi, R.A., Liu, J., Schäffer, A.A., Agarwala, R., Henthorn, P.S.: A novel mitofusin 2 mutation causes canine fetal-onset neuroaxonal dystrophy. Neurogenetics 12:223-32, 2011. Pubmed reference: 21643798. Doi: 10.1007/s10048-011-0285-6.
Further information is available at the Online Mendelian Inheritance in Animals website.