Note: Effective June 22, 2026, our laboratory has implemented long-read sequencing for repeat expansion panel testing, complementing our existing PCR/repeat-primed PCR–based approach.
Long-read sequencing provides more accurate repeat sizing and enables improved characterization of complex repeat expansions, enhancing the quality and detail of test results. Because this methodology requires high-quality, high-molecular-weight DNA, buccal swab specimens will no longer be accepted for repeat expansion panel testing. Blood and saliva specimens remain acceptable and are well suited for long-read sequencing analysis.
Our laboratory will provide saliva collection kits for patients requiring repeat expansion testing if requested by the ordering provider. Saliva kits will replace buccal swab kits for this purpose.
Buccal swab specimens continue to be accepted for Single Gene Repeat Expansion Analysis.
