Autosomal dominant mutation causing the dorsal ridge predisposes for dermoid sinus in Rhodesian ridgeback dogs

Area of Science:

• Veterinary Genetics
• Canine Dermatology

Background:

• The Rhodesian Ridgeback breed is characterized by a distinctive dorsal ridge.
• Dermoid sinus is a congenital abnormality observed in this breed.

Purpose of the Study:

• To determine the mode of inheritance for the dorsal ridge trait.
• To investigate the association between the dorsal ridge and the occurrence of dermoid sinus.

Main Methods:

• Segregation analysis of 87 litters (n=803) from Swedish Rhodesian Ridgebacks (1981-2002).
• Chi-squared analysis of 402 litters (n=3598) to assess genetic correlation.
• Data correction to mitigate bias in segregation ratios.

Main Results:

• The dorsal ridge is inherited in an autosomal dominant fashion.
• A predisposition to dermoid sinus was identified in dogs with the ridge trait.
• The estimated frequency of ridgeless offspring in the Swedish population is 5.6%.

Conclusions:

• Rhodesian Ridgebacks possessing the dorsal ridge trait have an increased risk of developing dermoid sinus.
• Understanding the genetic basis aids in managing congenital abnormalities in the breed.