behavior/neurological
• mice exhibit progressive degeneration of motor function without sensory loss
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• mice exhibit abnormal clasping of the legs and digits upon tail suspension at 6, but not 2, months of age
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• mice show a shorter latency to fall off the rotarod by 6 months of age
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• grip strength, measured across all 4 limbs, is reduced by 6 months of age
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• freely ambulating mice exhibit reductions in the percentage of overlapping footfalls by 8 months of age and lower frequency of diagonal contacts and compensatory increase in triagonal contacts by 6 months of age
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homeostasis/metabolism
• copper concentrations are decreased in the lumbar spinal cords at 6 and 12 months of age but not at 2 months
• motor neuron cell bodies of 8 month old mice show an accumulation of copper
• however, total copper concentrations and iron concentrations in the liver and brain are normal and serum ceruloplasmin activity and blood hemoglobin are normal
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muscle
• mice show a decrease in muscle mass by 12 months of age
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• mice exhibit a progressive late-onset muscle atrophy
• gastrocnemius muscle shows a loss of muscle bundles and the presence of inclusion bodies at 12, but not 6, months of age
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nervous system
• mice exhibit fewer motor neurons in the ventral horn by 12 months of age
• however, axonal diameter and myelin thickness of sciatic nerves is normal
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• symptomatic mice exhibit a decrease in the percentage of innervated neuromuscular junctions (NMJs) at 6 and 8 months which was further decreased by 12 months, indicating denervation of NMJs
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adipose tissue
• gonadal fat content is elevated at 12 months of age
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Mouse Models of Human Disease |
DO ID | OMIM ID(s) | Ref(s) | |
X-linked distal spinal muscular atrophy 3 | DOID:0111196 |
OMIM:300489 |
J:221066 |