FE Mt Dx
Feline mitochondrial disease
A number of different mitochondrial diseases have been identified in dogs, many with the genetic mutation identified. Only one putative mitochondrial disease has been reported in a cat. Clinical suspicion of feline encephaletic mitochondrial disease was raised in the presence of a progressive history of neurological dysfunction in cats. This is more common in young cats (under 2 years of age) and is often associated with a multi-systemic disorder. Genetic investigations in an affected cat revealed 2 polymorphisms within the tRNA-Leu(UUR) gene of the mitochondrial DNA. One of these mutations affects the Ac Stem loop in the secondary leaf structure of mitochondrial tRNA-Leu, which often is a pathogenic hotspot in humans for mitochondrial encephalopathy.
(i) Describe the key characteristics of disease presentation and progression for this type of genetic disease. (2 marks)
(ii) Describe in detail the inheritance processes and molecular mechanisms that can lead to variation in disease presentation of affected individuals and their offspring for this kind of genetic disease. (3 marks)
(iii) The polymorphisms associated with disease presentation may not necessarily be causative. State and describe what steps you would might take to narrow down on the true genetic causes of this disease. (3 marks)
(iv) What advice would you provide to clients wishing to breed from individuals carrying genetic markers for this disease? (2 marks)
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