Phenotypes Associated with This Genotype

Genotype
MGI:3763921

• Allelic Composition: Tg(HSA*LR)32aCath/?
• Genetic Background: involves: FVB/N

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

mortality/aging

premature death ( J:64493 )

• 41% of mice die by 44 weeks compared to less than 5% of wild-type mice

muscle

abnormal muscle fiber morphology ( J:64493 )

• mice exhibit a severe increase in central nuclei (in greater than 25% of fibers), atrophic fibers, ring fibers, and sarcoplasmic masses

• however, mice do not develop muscle weakness or wasting by 6 months of age

• muscle fiber cross-section area is increased (2710+/-550 um² compared to 1849+/-329 um² in Tg(HSA*SR)29Cath mice)

• muscle nuclei per muscle fiber is increased (2.9+/-0.7 compared to 0.8+/-0.14 in Tg(HSA*SR)29Cath mice)

• the number of muscle nuclei per fiber cross-section area is increased (1100+/-400 mm² compared to 450+/-40 mm² in Tg(HSA*SR)29Cath mice)

• the percentage of muscle nuclei that are central is increased (38+/-0.09% compared to 1.4+/-0.6% in Tg(HSA*SR)29Cath mice)

impaired muscle relaxation ( J:64493 )

• myotonia is observed as early as 4 weeks of age when muscle histology is normal

• mice exhibit abnormal hindlimb posture when they initiate movement after long periods of inactivity or when they are suspended by their tails

• 29 of 31 mice display myotonia

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
myotonic dystrophy type 1		DOID:11722	OMIM:160900	J:64493