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In-frame deletion in canine PITRM1 is associated with a severe early-onset epilepsy, mitochondrial dysfunction and neurodegeneration
- Source :
- Human Genetics, 1593–1609
- Publication Year :
- 2021
- Publisher :
- Springer Berlin Heidelberg, 2021.
-
Abstract
- We investigated the clinical, genetic, and pathological characteristics of a previously unknown severe juvenile brain disorder in several litters of Parson Russel Terriers. The disease started with epileptic seizures at 6 to 12 weeks of age and progressed rapidly to status epilepticus and death or euthanasia. Histopathological changes at autopsy were restricted to the brain. There was severe acute neuronal degeneration and necrosis diffusely affecting the grey matter throughout the brain with extensive intraneuronal mitochondrial crowding and accumulation of amyloid-β (Aβ). Combined homozygosity mapping and genome sequencing revealed an in-frame 6-bp deletion in the nuclear-encoded pitrilysin metallopeptidase 1 (PITRM1) encoding for a mitochondrial protease involved in mitochondrial targeting sequence processing and degradation. The 6-bp deletion results in the loss of two amino acid residues in the N-terminal part of PITRM1, potentially affecting protein folding and function. Assessment of the mitochondrial function in the affected brain tissue showed a significant deficiency in respiratory chain function. The functional consequences of the mutation were modeled in yeast and showed impaired growth in permissive conditions and an impaired respiration capacity. Loss-of-function variants in human PITRM1 result in a childhood-onset progressive amyloidotic neurological syndrome characterized by spinocerebellar ataxia with behavioral, psychiatric and cognitive abnormalities. Homozygous Pitrm1-knockout mice are embryonic lethal, while heterozygotes show a progressive, neurodegenerative phenotype characterized by impairment in motor coordination and Aβ deposits. Our study describes a novel early-onset PITRM1-related neurodegenerative canine brain disorder with mitochondrial dysfunction, Aβ accumulation, and lethal epilepsy. The findings highlight the essential role of PITRM1 in neuronal survival and strengthen the connection between mitochondrial dysfunction and neurodegeneration.
- Subjects :
- Male
medicine.medical_specialty
Respiratory chain
Status epilepticus
Saccharomyces cerevisiae
Grey matter
Biology
medicine.disease_cause
03 medical and health sciences
Epilepsy
0302 clinical medicine
Dogs
Oxygen Consumption
Internal medicine
Genetics
medicine
Animals
Dog Diseases
Genetics (clinical)
030304 developmental biology
Original Investigation
0303 health sciences
Mutation
Amyloid beta-Peptides
Neurodegeneration
1184 Genetics, developmental biology, physiology
Brain
Metalloendopeptidases
Neurodegenerative Diseases
medicine.disease
Disease gene identification
3. Good health
Mitochondria
Pedigree
medicine.anatomical_structure
Endocrinology
Spinocerebellar ataxia
Female
medicine.symptom
030217 neurology & neurosurgery
Subjects
Details
- Language :
- English
- ISSN :
- 14321203 and 03406717
- Volume :
- 140
- Issue :
- 11
- Database :
- OpenAIRE
- Journal :
- Human Genetics
- Accession number :
- edsair.doi.dedup.....f82aa0a3203ba0a48a91207222a80335