Expansion of short tandem repeats in the human genome underlies a set of neurological and neuromuscular repeat expansion disorders – most prominently Spinocerebellar Ataxias. Diagnosis of these disorders is based on the size and the specific motifs found of the repeat track. Historically, two methodologies have been utilized for diagnosis: PCR and Southern Blot. Long-read sequencing can consolidate legacy workflows and provide diagnostic insights that were previously inaccessible. Here, I will share how PacBio HiFi Sequencing and the PureTarget Repeat Expansion Panel help to modernize Quest Diagnostics’ genetics portfolio.