TAT
2-4 weeks
CPT Code
RFC1 - 0378U
FGF14 - 81479
ATXN1 - 81178
ATXN2 - 81179
ATXN3 - 81180
CACNA1A - 81184
ATXN7 - 81181
ATXN8OS - 81182
ATXN10 - 81183
ATN1 - 81177
FMR1 - 81243
FXN - 81284
PPP2R2B - 81343
TBP - 81344
NOP56 - 81479
Test Code
4103
Test Methods
Repeat Expansion Testing
Specimen Types Accepted
Blood
Saliva
Buccal
Cultured Cells
Extracted DNA
Documents
Additional Information
Our lab also offers RFC1 sequencing in addition to repeat expansion testing. To order, select Single Gene Sequencing on the requisition form. For test details, see Single Gene Sequencing Analysis.
Buccal swabs continue to be an acceptable sample type for any single gene test. If buccal samples are received, single gene repeat expansion testing will be performed by PCR/repeat-primed PCR methods.
As of June 22, 2026, single gene repeat expansion testing for RFC1, FGF14, FXN, NOP56, and ATXN10 may be done by long-read sequencing. Please send blood or saliva samples if long-read sequencing is desired.