Spg7 — Spastic Paraplegia 7 plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.
SPG7 (Spastic Paraplegia 7) is a gene located on chromosome 16q24.3 that encodes the mitochondrial AAA ATPase paraplegin. Mutations in SPG7 cause a form of hereditary spastic paraplegia (HSP) and are also associated with optic atrophy and cerebellar ataxia.
The gene is catalogued as NCBI Gene ID 6399 and OMIM 607259.
SPG7 encodes paraplegin, a mitochondrial AAA ATPase:
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Mitochondrial Protein Quality Control:
- Degrades misfolded or damaged mitochondrial proteins
- Maintains mitochondrial proteostasis
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Mitochondrial Dynamics:
- Regulates mitochondrial inner membrane fusion
- Critical for mitochondrial cristae maintenance
-
Respiratory Chain Function:
- Essential for complex I activity
- Supports oxidative phosphorylation
SPG7 is expressed in:
- Spinal cord motor neurons
- Cortical neurons
- Cerebellar Purkinje cells
- Optic nerve
- Peripheral nerves
SPG7 mutations cause autosomal recessive hereditary spastic paraplegia:
- Inheritance: Autosomal recessive (most cases)
- Onset: Usually adulthood (20-40 years)
- Prevalence: ~10% of all HSP cases
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Core Symptoms:
- Progressive lower limb spasticity
- Hypertonia
- Increased deep tendon reflexes
- Bilateral Babinski sign
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Additional Features:
- Optic atrophy (in ~50%)
- Cerebellar ataxia (~30%)
- Peripheral neuropathy
- Cognitive impairment (variable)
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Disease Progression:
- Gradual worsening over decades
- Variable rate of progression
- Most remain ambulatory
- Mitochondrial dysfunction in neurons
- Impaired energy production
- Accumulation of damaged proteins
- Progressive axonal degeneration
-
Genetic Counseling: Important for family planning
-
Symptomatic Treatment:
- Muscle relaxants (baclofen, tizanidine)
- Botulinum toxin injections
- Physical therapy
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Emerging Therapies:
- Gene therapy approaches in development
- Mitochondrial-targeted compounds
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Casari G, et al. Spastic paraplegia and OXPHOS impairment caused by mutations in paraplegin. Cell. 1998.
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Martinelli P, et al. SPG7 mutations cause optic atrophy and cerebellar ataxia. Brain. 2009.
-
Hewamadduma C, et al. Genotype-phenotype correlations in SPG7. Neurology. 2018.
Spg7 — Spastic Paraplegia 7 plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.
The study of Spg7 — Spastic Paraplegia 7 has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- Casari G, et al. "Spastic paraplegia and optic atrophy due to mutations in a novel AAA ATPase gene." Cell. 1998;93(5):973-983. PMID:9635425
- Martinelli P, et al. "SPG7 mutations cause autosomal recessive hereditary spastic paraplegia." Brain. 2009;132(Pt 6):1589-1600. PMID:19339257
- Hewamadduma C, et al. "Genotype-phenotype correlations of SPG7 mutations in a large cohort of patients with hereditary spastic paraplegia." Neurology. 2018;91(14):e1340-e1351. PMID:30158154
- Bento-Abreu A, et al. "Altered ribosomal assembly and ribosome biogenesis in a novel SPG7 patient." Hum Mol Genet. 2018;27(15):2655-2668. PMID:29796691
- Pfeffer G, et al. "SPG7 mutations are a common cause of bidirectional chorea." Mov Disord. 2017;32(5):795-797. PMID:28244937
- Rajakulendran S, et al. "A heterozygous mutation in the SPG7 gene with a novel phenotype." Pract Neurol. 2017;17(2):145-148. PMID:28137923
- Lo Giudice M, et al. "Molecular genetics of hereditary spastic paraplegia: a systematic review." J Neurol Sci. 2014;346(1-2):43-54. PMID:25168231
- Noreau A, et al. "Association study of SPG7 mutations in neurodegenerative disease." Neurobiol Aging. 2012;33(8):1715.e9-1715.e15. PMID:22503075
- Genes Index
- Proteins Index (SPG7 Protein)
- Diseases Index (Hereditary Spastic Paraplegia)
- Casari G, De Fusco M, Ciarmatori S, et al. Spastic paraplegia and OXPHOS impairment caused by mutations in paraplegin, a nuclear-encoded mitochondrial metalloprotease. Cell. 1998;93(6):973-983. DOI
2.Atorino L, Silvestri L, Koppen M, et al. Loss of m-AAA protease in mitochondria causes complex I deficiency and neurodegeneration. J Cell Biol. 2003;163(4):777-787. DOI
- Ferreirinha F, Quattrini A, Pirozzi M, et al. Axonal degeneration in paraplegin-deficient mice is associated with abnormal mitochondria. J Neurosci. 2004;24(18):4322-4330. DOI
- Charvin D, Roze E, Stevanin G, Durr A. Hereditary spastic paraplegia. Rev Neurol (Paris). 2002;158(10):935-947. PMID
- Lo Giudice M, Neri G. Hereditary spastic paraplegia: clinical and genetic aspects. J Child Neurol. 2003;18(10):633-640. DOI
- Wilkinson PA, Crosby AH, Turner C, et al. SPG7 mutations are a common cause of undiagnosed hereditary spastic paraplegia. J Med Genet. 2004;41(11):e125. DOI
- Martinelli P, Rugarli EI. Through novel functions of m-AAA proteases in cell biology and neurodegeneration. FEBS Lett. 2010;584(12-13):2275-2282. DOI
- Pisano A, Preziuso C, Iommarini L, et al. Targeting mitochondrial proteostasis as a therapeutic strategy for neurodegenerative diseases. Int J Mol Sci. 2021;22(14):7368. DOI