SCN8A and cerebellar ataxia: For example, in SNC8A null mice (medtg/medtg), the absence of NaV1.6 channels results in ataxia and early death of mice8, even though NaV1.1 and NaV1.2 fill the spots usually occupied for NaV1.6 and compensate for the lack of NaV1.69,10.