Progressive Retinal Atrophy, Type 3
            Breed: Miniature Dachshund/ longhaired
        
        
        
        
    
        
            Breeds
        
    
    
                
                Relevance Rating: There is some evidence or research available  for these breeds 
                
            
            
        
        General
        
            Disease Name
        
    
    
            Progressive Retinal Atrophy, Type 3
            
        
        
        
            OMIA
        
    
    
            1918
            
        
        
        
            Gene Name
        
    
    
            FAM161A
            
        
        
        
            Mutation
        
    
    
            c.1758-15_1758-16ins238
            
        
        
        
            Mutation 2
        
    
    
            A ~230bp insertion containing a 132bp short interspersed nuclear element (SINE), near the splice acceptor site of exon 5
            
        
        
        
            Test Type
        
    
    
            Genetic Disease/Disorder
            
        
        
        
            Details
        
    
    
            This form of PRA appears to be fairly late-onset, with diagnosis averaging at 5 years for the Tibetan Terrier, and 7 years for the Tibetan Spaniel. Signs of disease are not normally noticed by the owner until the disease has progressed to loss of night vision and on towards further vision loss leading to blindness. No mutations have previously been identifies for PRA in the breeds, however, it may be that there are other, unknown forms of PRA in the breeds. The Tibetan Spaniel seems to develop the disease either later or more slowly, as diagnosis averages around 7 years.
            
        
        
        
            Details 2
        
    
    
            Clinical descriptions for the Tibetan Terrier appear the same as late-onset PRA in other breeds. The mode of inheritance appears to be autosomal recessive, with diagnosis around 5 years. Age of onset not precise, as there is insufficient early-age data to confirm. It is very likely that the first clinical signs appear earlier than 5 years, as owners tend to notice the onset once the disease has impacted vision. No mutations have previously been associated with PRA in the breed. The Tibetan Spaniel seems to develop the disease either later or more slowly, as diagnosis averages around 7 years. It may be that there are other, unknown forms of PRA in the breeds.
            
        
        
        
            Published
        
    
    
            Downs, L.M., Mellersh, C.S. : An Intronic SINE Insertion in FAM161A that Causes Exon-Skipping Is Associated with Progressive Retinal Atrophy in Tibetan Spaniels and Tibetan Terriers. PLoS One 9:e93990, 2014. Pubmed reference: 24705771. DOI: 10.1371/journal.pone.0093990.
            
        
        
        
            Published 2
        
    
    
            Downs,L.M.,Aguirre,G.D.: FAM161AandTTC8areDifferentiallyExpressedinNon-AllelelicEarlyOnsetRetinalDegeneration.AdvExpMedBiol854:201-7,2016.Pubmedreference:26427412.DOI:10.1007/978-3-319-17121-0_27.
            
        
        
        
            Body/System/Process
        
    
    
            Eye
            
        
        
        
            OMIA Url
        
    
    
        
            Inheritance
        
    
    
            AR
            
        
        Breed Specific Info
        
            Researched Breeds
        
    
    
            Tibetan Terrier, Tibetan Spaniel
            
        
        
        
            Breed-specific 1
        
    
    
            Tibetan Spaniel, Tibetan Terrier
            
        
        
        
            Breed-specific 1 Details
        
    
    
            Publication describes strong association between mutation and disease in Tibetan Spaniels. The mutation was also homozygous in four Tibetan terriers with confirmed PRA. At least one other form of PRA considered likely in TTs. Confirmation the mutation causes exon skipping was confirmed by qRT-PCR is included. Downs et al., (2014) An Intronic SINE insertion in FAM161A that causes exon-skipping is associated with progressive retinal atrophy in Tibetan Spaniels and Tibetan Terriers. PLoS One, 9, e93990.
            
        
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