Mapping the mutation causing lens luxation in several terrier breeds

Area of Science:

• Veterinary Genetics
• Ophthalmology
• Canine Genetics

Background:

• Primary lens luxation (PLL) is a common, inherited, and debilitating eye condition in terriers.
• PLL leads to pain and blindness, impacting numerous dog breeds.

Purpose of the Study:

• To investigate the genetic basis of primary lens luxation (PLL) in dogs.
• To identify specific chromosomal regions associated with PLL across various breeds.

Main Methods:

• Analysis of veterinary medical and CERF case records over 10 years, encompassing 85 breeds.
• Genome-wide microsatellite association analysis in Miniature Bull Terriers and Lancashire Heelers.
• Sequencing of TJP1 gene exons and splice junctions in affected and control dogs.

Main Results:

• A significant association of microsatellite alleles with PLL was found in a 6.3-Mbp region on chromosome 3.
• This chromosomal region also showed association with PLL in Tibetan Terriers.
• Polymorphisms in the TJP1 gene were identified but are unlikely to be the causative mutations for PLL.

Conclusions:

• A specific region on canine chromosome 3 is strongly associated with primary lens luxation.
• The causative mutation for PLL has not been definitively identified, despite TJP1 being a positional candidate.