December 14, 2017

A large deletion in RPGR causes XLPRA in Weimaraner dogs

Progressive retinal atrophy (PRA) is one of several diseases concerning the eyes in certain dog breeds, especially Weimaraners. It refers to the deterioration of vision over time, eventually leading to blindness. The cause of this genetic disposition is inbreeding within small populations of Weimaraners. This study looks at a group of dogs pulled from a population in Germany. Researchers started looking at data from veterinarians in 2015 and noticed a significant rise of PRA in Weimaraners, specifically in dogs around the age of two and a half years. The PRA occurs when there is a mutation in one gene that is similar to the gene in humans that is associated with vision. The deletion of many X-linked retinitis pigmentosa GTPase regulator (RPGR) exons has been the main cause of this disease.

Researchers looked at the records of 108 dogs, most of which were healthy; the blood samples of those dogs were taken. However, only two healthy dogs and two diseased dogs had the exons of their whole genomic sequence were analyzed. The healthy dogs had to be older than two and a half years because most of the onsets of the disease were around that age. Others were partially analyzed.

After the use of polymerase chain reaction (PCR), the DNA strands were lengthened so they could be observed more easily. While the researchers already knew where the mutations had occurred in the genome, the findings from the PCR strengthened their claims. Ultimately, the researchers concluded that prior to the breeding of two Weimaraners, it would be in the best interest of the future offspring for the owners to examine the genes of their dogs, especially the RPGR exons, to see if the offspring would be healthy.

Regina Kropatsch, Denis A. Akkad, Matthias Frank, Carsten Rosenhagen, Janine Altmüller, Peter Nürnberg, Jörg T. Epplen and Gabriele Dekomien. “A large deletion in RPGR causes XLPRA in Weimaraner dogs.Canine Genetics and Epidemiology: 08 July 2016. Web.

Original Article: https://cgejournal.biomedcentral.com/articles/10.1186/s40575-016-0037-x

Summary by Ford Young