Donate
Progressive Retinal Atrophy, Type 3
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.
