Spider Lamb Syndrome

Quick Summary

Ovine hereditary chondrodysplasia (spider lamb syndrome) is a semi-lethal inherited disorder associated with skeletal deformities in young sheep.

Phenotype: Ovine hereditary chondrodysplasia (spider lamb syndrome) is associated with skeletal deformities in young sheep. Structural abnormalities observed in afflicted lambs include facial defects, humped or twisted spines, abnormally long legs, bent and/or splayed legs, flattened ribs, and an underdeveloped musculature. While the deformities may not be apparent at birth, they are often visible by 4-6 weeks of age.

Mode of Inheritance: Autosomal recessive

Alleles: N = Normal/Unaffected, S = Spider lamb syndrome

Breeds appropriate for testing: Suffolk, Hampshire, Southdown, Shropshire, Oxford, and other breeds and crossbreeds derived from Suffolk stock in the US

Explanation of Results:

  • Sheep with N/N genotype will not have spider lamb syndrome and cannot transmit this spider lamb syndrome variant to their offspring.
  • Sheep with N/S genotype will not be affected by spider lamb syndrome, but are carriers. They will transmit this spider lamb syndrome variant to 50% of their offspring. Matings between two carriers result in a 25% chance of producing a lamb with spider lamb syndrome.
  • Sheep with S/S genotype will have spider lamb syndrome, a semi-lethal disorder associated with skeletal deformities. 
Price

$20 one test per animal

Additional Details

Ovine hereditary chondrodysplasia (spider lamb syndrome) is a semi-lethal inherited disorder associated with skeletal deformities in young sheep. Structural abnormalities observed in afflicted lambs include facial defects, humped or twisted spines, abnormally long legs, bent and/or splayed legs, flattened ribs, and an underdeveloped musculature. While the deformities may not be apparent at birth, they are often visible by 4-6 weeks of age. These combined musculoskeletal defects were first observed in black-faced lambs in the mid 1970’s.

Research into the cause of spider lamb syndrome identified a mutation within the gene for fibroblast growth factor receptor 3 (FGFR3). Because the syndrome is a recessive genetic disorder, a lamb is only afflicted if both parents pass on the mutation. Thus, it is critical to identify carriers of the mutation. Carriers (animals with only one copy of the mutation) are structurally normal with no evidence of disease.

The VGL is licensed by Utah State University to perform testing of the FGFR3 mutation. Test results allow breeders to select appropriate breeding pairs to eliminate this condition from their herd.

Turnaround Time
2-6 business days
Type of Sample

Species

Type of Test

Results Reported As
Test Result Spider Lamb Syndrome
N/N Animal does not have the FGFR3 mutation.
N/S Carrier. Animal has one copy of the FGFR3 mutation. Breedings between carriers are expected to produce 25% affected lambs.
S/S Affected. Animal has two copies of the FGFR3 mutation.
References

Beever, J.E., Smit, M.A., Meyers, S.N., Hadfield, T.S., Bottema, C.K., Albretsen, J.C., & Cockett, N.E. (2006). A single-base change in the tyrosine kinase II domain of ovine FGFR3 causes hereditary chondrodysplasia in sheep. Animal Genetics, 37(1), 66-71. doi: 10.1111/j.1365-2052.2005.01398.x

License Info

The Veterinary Genetics Laboratory, University of California, Davis is licensed by Utah State University to perform testing of the FGFR3 mutation.