Clinical signs include motor, behavioral, and sensory dysfunction, ataxia (incoordination), hypermetria (overreaching or excessive of movement), dysmetria (disturbance in the control in the range of muscular movement), carpal deviation, wide stance, dysphagia (swallowing difficulties), head tremors, hyperactive reflex responses, and kyphosis (abnormal dorsal arching to the spine), and loss of learned behavior. Dogs with this disease have dramatically shortened lifespans and are generally humanely euthanized before 36 months of age due to the severity of the condition.
Fucosidosis is a lysosomal storage disease (LSD). This is because the gene that is mutated in affected dogs is the FUCA1 gene, which encodes an enzyme called alpha-L-fucosidase, which is found within the lysosomes of a wildtype individual. Alpha-L-fucosidase is responsible for cleaving off a sugar molecule called fucose, which in the absence of the enzyme, builds up in high concentrations in the cytoplasms of the affected individuals’ cells.
36 months
Autosomal recessive
Fucosidosis is a lysosomal storage disease (LSD) in which a lysosomal enzyme called alpha-L-fucosidase is absent or non-functional. Alpha-L-fucosidase is responsible for cleaving off a sugar molecule called fucose, which in the absence of the enzyme, builds up in high concentrations in the cytoplasm of the affected individuals’ neurological cells.
FUCA1 and NM_001003250.1:c.379_392delGCGGCGGGGGCCCG
Explanation of Results
| Genotype |
Phenotype |
Interpretation |
| 2-2 (Homozygous Disease Variant) |
Unhealthy (Affected) |
Homozygous Affecteds (2-2) are expected to develop signs consistent with Fucosidosis and all of their offspring will inherit a disease variant allele. Parents, offspring and relatives should also be tested. You may choose to contact us for a consultation on the management of this disease. 1 = Normal allele; 2 = Variant allele. |
| 1-2 (Heterozygous) |
Healthy (Carrier) |
Heterozygous Carriers (1-2) are not expected to develop signs of Fucosidosis but each of their offspring has a chance of inheriting a disease variant allele. Parents, offspring and relatives should also be tested. 1 = Normal allele; 2 = Variant allele. |
| 1-1 (Homozygous Normal) |
Healthy (Normal, Clear) |
Homozygous Normals (1-1) are not expected to develop signs of Fucosidosis and none of their offspring will inherit the disease variant allele. 1 = Normal allele; 2 = Variant allele. |
Skelly BJ, Sargan DR, Winchester BG, Smith MO, Herrtage ME, Giger U. Genomic screening for fucosidosis in English Springer Spaniels. Am J Vet Res. 1999 Jun;60(6):726-9. PMID: 10376901.
Smith MO, Wenger DA, Hill SL, Matthews J. Fucosidosis in a family of American-bred English Springer Spaniels. J Am Vet Med Assoc. 1996 Dec 15;209(12):2088-90. PMID: 8960193.
Skelly BJ, Sargan DR, Herrtage ME, Winchester BG. The molecular defect underlying canine fucosidosis. J Med Genet. 1996 Apr;33(4):284-8. doi: 10.1136/jmg.33.4.284. PMID: 8730282; PMCID: PMC1050576.
Occhiodoro T, Anson DS. Isolation of the canine alpha-L-fucosidase cDNA and definition of the fucosidosis mutation in English Springer Spaniels. Mamm Genome. 1996 Apr;7(4):271-4. doi: 10.1007/s003359900081. PMID: 8661697.
Keller CB, Lamarre J. Inherited lysosomal storage disease in an English springer spaniel. J Am Vet Med Assoc. 1992 Jan 15;200(2):194-5. PMID: 1559875.
Friend SC, Barr SC, Embury D. Fucosidosis in an English springer spaniel presenting as a malabsorption syndrome. Aust Vet J. 1985 Dec;62(12):415-20. doi: 10.1111/j.1751-0813.1985.tb14124.x. PMID: 3833197.
