Table 7.

ATXN7 Technical Considerations

Technical IssueComment [Reference]
Sequence of repeatCAG
Methods to detect expanded allele (See Table 8.)PCR w/fragment analysis, triplet-primed PCR, & Southern blotting
Somatic instabilityAlleles w/abnormal number of CAG repeats may display somatic instability of the repeat, appearing as "smeared" expanded alleles w/multiple distinct expansion alleles on PCR or Southern blot analysis [Gu et al 2000, Katagiri et al 2015].
Germline instabilityThe CAG repeat size tends to expand w/transmission to successive generations, w/more marked expansions seen in affected offspring of affected males [Gouw et al 1998].

From: Spinocerebellar Ataxia Type 7

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