A team of researchers from the University of California that was led by Danika Brannasch discovered a genetic mutation that causes chondrodystrophy in some dog breeds. Chondrodystrophy is a skeletal disorder that results in abnormal intervertebral discs and shorter legs. The condition is common in certain dog breeds, such as pugs, dachshunds, and bulldogs.
According to Brannasch, chondrodystrophy has a strong correlation with intervertebral disc disease (IVDD) because dogs that have IVDD usually have chondrodystrophy as well. IVDD is a neurological condition that leads to the herniation of abnormal discs and can potentially lead to paralysis.
The first dog breed that was focused on was the toller breed. They discovered that there was a region of significance on chromosome 12 that affected long bone growth and noticed the same DNA sequence in other chondrodystrophic breeds. They looked at DNA samples from dogs with IVDD and found the same sequence. They discovered that there was an FGR4 retrogene insertion in the region of interest in chromosome 12, which is involved in development. A retrogene is DNA that was made from RNA via reverse transcription. Mutations in the retrogene's receptor can cause dwarfism in humans. I was interested in this article because it reminded me of one of my dogs. He was a mixture between a Labrador and a Basset hound, so he developed a really bad back. I thought that this discovery was significant because it could inspire research that seeks to breed out the trait in certain breeds once additional data is found due to chondrodystrophy being inheritable. This discovery could also improve the treatment of animals that have the condition. It could also inspire new methods for treatment and it might lead to an effective and less expensive option for pet owners. The discovery could also provide an interesting model for similar spinal conditions in humans, which could promote a greater understanding of where these conditions could come from and potential ways to treat them.
References Emily A. Brown, Peter J. Dickinson, Tamer Mansour, Beverly K. Sturges, Miriam Aguilar, Amy E. Young, Courtney Korff, Jenna Lind, Cassandra L. Ettinger, Samuel Varon, Rachel Pollard, C. Titus Brown, Terje Raudsepp, Danika L. Bannasch. FGF4retrogene on CFA12 is responsible for chondrodystrophy and intervertebral disc disease in dogs. Proceedings of the National Academy of Sciences, 2017; 201709082 DOI: 10.1073/pnas.1709082114