Phenotypes Associated with This Genotype

Genotype
MGI:3663375

• Allelic Composition: Smn1^tm1Hung/Smn1^tm1Hung; Tg(SMN2)2Hung/Tg(SMN2)2Hung
• Genetic Background: involves: 129P2/OlaHsd * FVB/N

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

mortality/aging

premature death ( J:59313 )

• mice with an intermediate phenotype (type 2) die at approximately 2-4 weeks

postnatal lethality, incomplete penetrance ( J:59313 )

• mice with the most severe phenotype (type 1) die before P10

• mice with an intermediate phenotype (type 2) die at approximately 2-4 weeks

• mice with a mild phenotype (type 3) live a normal lifespan

nervous system

abnormal astrocyte morphology ( J:59313 )

• presence of glial bundles observed in anterior spinal root of type 1 mice

abnormal motor neuron morphology ( J:59313 )

• selective loss of thick myelinated fibers observed in anterior spinal root of type 1 mice

decreased motor neuron number ( J:59313 )

• loss of large motor neurons in anterior horns of spinal cord with appearance of empty cell beds

• phenotype is not observed in type 3 mice

chromatolysis ( J:59313 )

• exhibited in motor neurons of anterior horn of type 1 mice

axon degeneration ( J:59313 )

• exhibited in anterior spinal roots

• phenotype is not observed in type 3 mice

muscle

abnormal skeletal muscle fiber morphology ( J:59313 )

decreased skeletal muscle fiber diameter ( J:59313 )

• decreased diameter of muscle fibers in tail

increased skeletal muscle fiber size ( J:59313 )

• atrophic fibers associated with hypertrophic type 1 fibers in type 1 mice

decreased skeletal muscle fiber number ( J:59313 )

• fewer muscle fibers in trunk and limb muscles

muscular atrophy ( J:59313 )

• atrophy of muscle bundles in tail, trunk and limb muscles

limbs/digits/tail

abnormal tail morphology ( J:59313 )

• decreased diameter of muscle fibers, atrophy of muscle bundles, group atrophy and subcutaneous edema

• edema is more severe in type 3 than in type 2 mice and rare in type 1 mice

tail necrosis ( J:59313 )

• 50% of type 1 and 2 mice develop chronic necrosis from the tip of the tail to the root

short tail ( J:59313 )

• exhibited by mice with the type 3 phenotype

thick tail ( J:59313 )

• exhibited by mice with the type 3 phenotype

homeostasis/metabolism

extremity edema ( J:59313 )

• subcutaneous edema of tail, most severe in type 3 mice and rare in type 1

• subcutaneous edema of hindlimbs

behavior/neurological

hindlimb paralysis ( J:59313 )

• exhibited in some type 2 mice

growth/size/body

decreased body weight ( J:59313 )

• exhibited by all three phenotypes, decrease is proportionate to severity of symptoms

integument

hairless ( J:59313 )

• type 1 mice do not develop fur

cellular

tail necrosis ( J:59313 )

• 50% of type 1 and 2 mice develop chronic necrosis from the tip of the tail to the root

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Werdnig-Hoffmann disease		DOID:13137	OMIM:253300	J:59313