Background/Aims: The diagnostic odyssey experienced by patients living with rare diseases is a major barrier to obtaining appropriate clinical management, access to therapies and wider support. To overcome this challenge, we set up a Syndromes Without A Name (SWAN) clinic in Wales with the sole purpose of finding a diagnosis for patients with rare diseases who had undergone NHS genetic testing but remain undiagnosed. A major component of the SWAN clinic is the development of a genomic reanalysis pipeline. To date, we have received referrals for 234 patients, of which 159 met our inclusion criteria. Of these, 42 had sequence data available (mixture of gene-panels, whole exome and whole genome) and were referred for genomic reanalysis. Our genomic reanalysis strategy utilised the Congenica variant prioritisation software and a gene-agnostic model. Variants were ranked based on Exomiser scores, de novo status (if trio data available), REVEL score and inheritance models for compound heterozygous, autosomal recessive and X-linked. Variants were further prioritised based on HPO terms derived from an in-person clinical re-evaluation of each patient. To date, we have completed the genetic reanalysis of 42 patients and provided novel diagnoses for 2patients. As expected for a SWAN cohort, we have also identified a number of novel candidate genes (n=13) that have been uploaded to GeneMatcher to identify further patients.