Canine Hereditary Deafness Study May Shed Light on Human Hereditary Hearing Defects Also
Finnish researchers were the first to determine the cause of hereditary, early-onset non-indromic canine deafness in Rottweilers. The genetic defect has been identified in a gene relevant to the sense of hearing. The study may also promote understanding of the mechanisms of hearing loss in humans.
Hearing loss is the most common sensory impairment and a complex problem in humans, with varying causes, severity and age of onset. Deafness and hearing loss are quite common in dogs as well, but the genetic variants underlying the inherited form of the disorder are so far poorly understood.
Researchers at the University of Helsinki and the Folkhalsan Research Center focused on a rare type of hearing loss seen in Rottweilers. It begins early in infancy and progresses to deafness by the age of a few months. A similar type of hearing loss was also seen in a small number of mixed breed dogs, the majority of which had Rottweiler ancestry.
We have identified the variant in the LOXHD1 gene, which plays a key role in cilia function of cochlear sensory cells. Although the exact mechanism of deafness is not known, variants of the same gene cause hereditary hearing loss in humans and mice. “
Docent Marjo Hytonen, University of Helsinki and Folkhalsan Research Center
Hearing loss caused by the defective LOXHD1 gene is an inherited recessive trait, which means that in order to develop the disorder, the dog must have two copies of the defective gene, one from the sire and one from the dam.
“Through our collaborative partner, we were fortunate to study the prevalence and breed specificity of the variant gene in a unique global dataset of some 800,000 dogs. No survey of a similar scope has been carried out. previously published, “says Professor Hannes Lohi of the University of Helsinki and the Folkhalsan Research Center.
New individual dogs that had inherited the genetic defect and were also found to be deaf were identified during screening.
“This reinforces the significance of our discovery. Thanks to our discovery of genes, dogs used for breeding can now be tested for the defect. This helps prevent combinations that could result in puppies losing their hearing.”
The recent study is part of a research program led by Professor Lohi and studying the genetic background of inherited diseases. Several projects are currently underway whose objectives include determining the genetic causes of hearing loss.
According to Marjo Hytonen, the preliminary results are promising.
“We have observed that unknown hereditary congenital deafness and deafness in adults occur in several breeds of dogs. In addition to dogs, the preliminary results open up new avenues for investigating hereditary human hearing defects.
Hytönen, MK, et al. (2021) Missense variant in LOXHD1 is associated with canine nonsyndromic hearing loss. Human genetics. do I.