Dermatosparaxis / dEDS / Ehlers-Danlos type VII (ADAMTS2-related) - Dorper sheep

What does this test examine?

This DNA test analyses two variants in the ADAMTS2 gene in sheep: c.424G>T with protein notation p.E142* and c.673G>A with protein notation p.V225M. The condition is known as dermatosparaxis, Dermatosparaxis Ehlers-Danlos syndrome, dEDS, Ehlers-Danlos syndrome type VII, EDS type VIIC, inherited collagen disorder and inherited skin fragility.

The test is especially relevant for Dorper and White Dorper lines and crosses with Dorper genetics. Dermatosparaxis affects collagen quality in skin and connective tissue. As a result, affected lambs can have extremely fragile skin that tears easily during normal movement, handling or contact.

What does dermatosparaxis mean?

ADAMTS2 encodes an enzyme involved in processing procollagen into functional collagen. When both copies of a harmful ADAMTS2 variant are present, this process is severely disturbed. Affected lambs may show very thin, stretchable or tear-prone skin, skin flaps, deep wounds, skin separation around joints, poor wound healing, bleeding or severe injuries at a young age.

This condition matters for animal welfare and breeding policy. Severely affected lambs often have a poor outlook; in described cases, the severity of the skin lesions regularly leads to death or euthanasia. Carriers with one variant copy are usually clinically normal, but they can pass the variant to their offspring.

Inheritance and result

Dermatosparaxis caused by these ADAMTS2 variants is inherited as an autosomal recessive trait. A clear animal has no copy of the tested variant. A carrier has one copy and is mainly important for breeding planning. An animal with two copies of the same tested variant is genetically affected.

Because this analysis examines two ADAMTS2 variants, each subanalysis is reported separately. This makes clear whether the animal is clear, carrier or has two copies for the specific variant tested. The result helps avoid risk matings in breeding programmes.

Practical value of this test

This test gives breeders a concrete way to identify carriers early and plan matings more deliberately. That is especially valuable in Dorper and White Dorper populations where a recessive disorder can remain hidden until two carriers are mated.

Why test?

• Helps distinguish clear animals and carriers before selection or sale.
• Makes it possible to avoid carrier-carrier matings and prevent affected lambs.
• Supports animal welfare by reducing the risk of severe skin fragility in offspring.
• Helps preserve valuable bloodlines responsibly without excluding every carrier unnecessarily.
• Adds confidence for purchase decisions, mating plans and healthy flock development.