Phenotypes Associated with This Genotype

Genotype
MGI:5500085

• Allelic Composition: Cacna1a^smrl/Cacna1a^smrl
• Genetic Background: CXB10/HiAJ-Cacna1a^smrl/GrsrJ

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

Cacna1a^smrl/Cacna1a^smrl mouse (right) showing smaller body size and rolling on its side when walking compared to heterozygous control (left)

behavior/neurological

abnormal motor coordination/balance ( J:198844 )

• as soon as pups begin to try to walk there is clear weakness and difficulty in locomotion characterized as having ataxia with a severe side-to-side gait with swaying hindquarters, splaying hind legs, and the body held close to the ground, and homozygotes often fall over and have difficulty righting

impaired righting response ( J:198844 )

ataxia ( J:198844 )

impaired balance ( J:198844 )

impaired limb coordination ( J:198844 )

mortality/aging

abnormal survival ( J:198844 )

• diminished litter size, fewer than expected homozygotes born, and stillborn and postnatal lethality of what are likely homozygotes

• heterozygous intercrosses also produce fewer homozygotes than expected and have a higher than normal percent of stillborn and pups dying in the first week after birth

decreased survivor rate ( J:198844 )

neonatal lethality, incomplete penetrance ( J:198844 )

• a high percentage of pups predicted to be homozygotes are found dead or missing prior to phenotypic assessment at approximately 1 week of age

perinatal lethality, incomplete penetrance ( J:198844 )

• a high percentage of stillborn, which are thought to be homozygotes due to having fewer than expected homozygotes at phenotypic onset

reproductive system

decreased litter size ( J:198844 )

♀ • homozygous females bred to heterozygous males have an average litter size less than 3, and when bred to wildtype males have an average litter size of 3.8, still smaller than normal

vision/eye

vision/eye phenotype ( J:198844 )

♂N • ophthalmoscopic examination of 2 males at approximately 25 weeks of age found no abnormalities

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
spinocerebellar ataxia type 6		DOID:0050956	OMIM:183086	J:222308