[Achievements and Expectations of the Rare Disease Diagnostic Support Program in the Republic of Korea].

Objectives: The Rare Disease Diagnostic Support Program in the Republic of Korea aims to improve early diagnosis and diagnostic yield for patients with rare diseases, particularly for those residing in non-metropolitan areas, by providing whole genome sequencing (WGS) services through regional medical institutions. This study evaluated the performance of the program, focusing on its clinical utility, including early diagnosis and treatment linkage, and its policy impact related to patient benefits. Methods: From August 2024, WGS was performed on 410 patients with suspected rare diseases at 23 institutions outside the metropolitan area. A one-stop diagnostic pathway was established to perform sample collection, test referral, report delivery, and genetic counseling within a single clinical flow based on the patient's location of residence. Sequencing was performed by external laboratories. Results: Among the 410 patients, pathogenic variants were identified in 129 (31.5%), with a turnaround time of 28 days. Of those diagnosed, 78.2% received treatment benefits via national programs such as co-payment exemption and medical expense support programs. Approximately 30% of the patients were eligible for therapeutic intervention, particularly medication or dietary therapy. Family genetic testing of three members identified potential carriers or high-risk groups in 28 households (65.1%). Consent for secondary findings was 99.0%, with clinically significant variants found in 3.9% of cases. Conclusions: The program demonstrated clinical value by improving diagnostic accessibility, reducing regional disparities, facilitating timely treatment, and supporting preventive care through family risk identification. These findings support the need for sustainable expansion of genome-based diagnostic services in the national health policy.