Phenotypes Associated with This Genotype

Genotype
MGI:2651696

• Allelic Composition: Atxn7^tm1Hzo/Atxn7⁺
• Genetic Background: involves: 129S7/SvEvBrd * C57BL/6

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

mortality/aging

premature death ( J:82072 )

• death at 14 to 19 weeks of age

• mice exhibit normal growth until 5 weeks of age, with little to no weight gain thereafter; mice did not eat or drink during terminal stages prior to death

behavior/neurological

ataxia ( J:82072 )

• gait ataxia displayed by 8 to 9 weeks of age

impaired coordination ( J:82072 )

• impaired motor coordination in rotarod test

decreased locomotor activity ( J:82072 )

• exhibited at terminal stage prior to death

myoclonus ( J:82072 )

• some mice developed myoclonic seizures around 12 weeks of age

muscle

myoclonus ( J:82072 )

• some mice developed myoclonic seizures around 12 weeks of age

reproductive system

female infertility ( J:82072 )

♀ • females were infertile at 8 weeks of age

male infertility ( J:82072 )

♂ • males showed reduced fertility at 16 weeks of age

skeleton

kyphosis ( J:82072 )

vision/eye

decreased retina photoreceptor cell number ( J:82072 )

• loss of ~20% of photoreceptors from outer nuclear layer at 15 weeks of age; retinal dysfunction occurring prior to the loss of photorecptors, cone dysfunction occuring prior to rod dysfunction; accumulation of Sca7 protein, forming microaggregates by 8 weeks of age

short photoreceptor outer segment ( J:82072 )

• shortening of outer segments

blepharoptosis ( J:82072 )

• eyes receded and ptosis developed as mice aged

thin retina inner plexiform layer ( J:82072 )

• thinning of inner plexiform layer

nervous system

myoclonus ( J:82072 )

• some mice developed myoclonic seizures around 12 weeks of age

decreased brain size ( J:82072 )

abnormal cerebellum morphology ( J:82072 )

• progressive accumulation of Sca7 protein, first evident at 5 weeks of age

decreased Purkinje cell size ( J:82072 )

• cell bodies were observed to be smaller than those of wild-type at 16 wks of age; normal numbers of Purkinje cells and their dendritic arbors are present at 16 wks of age

decreased retina photoreceptor cell number ( J:82072 )

• loss of ~20% of photoreceptors from outer nuclear layer at 15 weeks of age; retinal dysfunction occurring prior to the loss of photorecptors, cone dysfunction occuring prior to rod dysfunction; accumulation of Sca7 protein, forming microaggregates by 8 weeks of age

short photoreceptor outer segment ( J:82072 )

• shortening of outer segments

decreased post-tetanic potentiation ( J:82072 )

• impaired posttetanic potentiation (PTP)

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
spinocerebellar ataxia type 7		DOID:0050958	OMIM:164500	J:82072