Osteogenesis imperfecta

Osteogenesis imperfecta (OI) is a hereditary disease affecting wire-haired and short-haired dachshunds. The disease is characterized by rarefaction of bones and teeth and the affected dogs show typical clinical symptoms already within the first three months of their life. A very serious complication of this disease is osteopenia that causes insufficient formation of lamellar bone particularly in long bones, vertebral column and skull leading to increased bone fragility. In the teeth, the dentine layers are thin and lack the characteristic tubular pattern.  The most important protein of the bone structure is collagen type I that is the most abundant protein in the body and the highly ordered fibril structure of this type I collagen is responsible for its mechanical properties and gives the bones elasticity. Defects in the structure of the highly ordered collagen I result in loss of bone stability and subsequent bone and teeth fragility and thus in development of osteogenesis imperfecta.

Drögemüller et al. (2009) have identified c.977C>T mutation in SERPINH1 (serpin peptidase inhibitor, collagen binding protein 1) gene that is responsible for the development of osteogenesis imperfecta in dachshunds. Eckhardt et al. (2013) performed population screening and analysis of c.977C>T mutation in 1352 dachshunds from 12 European countries. The highest frequency (17.3 %) of the OI-carriers was found in wire-haired dachshunds. Tests were performed across all different size varieties (standard, miniature, kaninchen dachshunds) in which a similar frequency of OI carriers was found. The mutated allele was also found in smooth-haired dachshunds and the possibility of its occurrence to a small extent in long-haired dachshunds cannot be excluded.

OI is autosomal recessive inherited disease. That means the disease affects dogs with P/P (positive / positive) genotype only. The dogs with P/N (positive / negative) genotype are clinically without any symptom. They are genetically considered carriers of the disease (heterozygotes). In offspring of two heterozygous animals following genotype distribution can be expected: 25 % N/N (healthy non-carriers), 25 % P/P (affected), and 50 % N/P (healthy carriers). Because of high risk of producing affected offspring, mating of two N/P animals (carriers) can not be recommended.

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Reference:

Drögemüller C, Becker D, Brunner A, Haase B, Kircher P, et al. (2009) A Missense Mutation in the SERPINH1 Gene in Dachshunds with Osteogenesis Imperfecta. PLOS Genetics 5(7): e1000579.

Eckardt, J., Kluth, S., Dierks, C., Philipp, U., Distl, O. : Population screening for the mutation associated with osteogenesis imperfecta in dachshunds. Vet Rec 172:364, 2013. Pubmed reference: 23315765.

Seeliger, F., Leeb, T., Peters, M., Brügmann, M., Fehr, M., & Hewicker-Trautwein, M. (2003). Osteogenesis Imperfecta in Two Litters of Dachshunds. Veterinary Pathology, 40(5), 530–539.