National Rare Diseases Registry System (NRDRS): China's first nation-wide rare diseases demographic analyses.

Background: China has made tremendous progresses in serving the needs of its people living with rare diseases in the past decade, especially over the last 5 years. The Chinese government's systematic approach included a series of coordinated initiatives, amongst these are: forming the Rare Disease Expert Committee (2016), funding the "Rare Diseases Cohort Study" (2016-2020), and publishing its first "Rare Disease Catalog" (2018). Herein, we present the National Rare Diseases Registry System (NRDRS)-China's first national rare diseases registry, and the analysis of cases registered in the first 5 years ending Dec 31, 2020.

Results: The total 62,590 cases covered 166 disease/disease types, forming 183 disease cohorts. The data from nearly 22% of them (13,947 cases) is also linked to valuable biological samples. The average age of definitive diagnosis was 30.88 years; 36.07% of cases were under 18 years of age. Regional distribution analysis showed 60% of cases were from the more developed, wealthier East and North China, suggesting the local availability of quality care and patients' financial status were key access factors. Finally, 82.04% of cases were registered from the five clinical departments: Neurology, Endocrine, Hematology, Cardiovascular, and Nephrology, suggesting that either these are most affected by rare diseases, or that there were disease non-specific ascertainment factors.

Conclusions: The preliminary analysis of the first 5-year's data provides unique and valuable insight on rare disease distribution in China, and higlights the directions for enhancing equity, scale and utility.