Claims-Based Diagnostic Registration Patterns and Clinical Burden of Selected Common Aneuploidies in Korean Children: A Nationwide HIRA Study (2009–2023)

Background: Selected common aneuploidies, including Down, Edwards, Patau, Turner, and Klinefelter syndromes, are important causes of congenital anomalies and diverse clinical morbidities. However, nationwide evidence regarding the recent diagnostic registration patterns, clinical outcomes, and healthcare burdens in South Korea remains limited. Methods: We conducted a nationwide descriptive analysis using claims data from the Health Insurance Review and Assessment Service (HIRA) of South Korea between 2009 and 2023. Among individuals aged 0–14 years, we evaluated period-based administrative registration frequency and ratios relative to live births, age at diagnosis, comorbidities including congenital heart disease (CHD) and epilepsy, in-hospital mortality, and first-year healthcare expenditures following the first observed claims-code date. Results: Among the 5,586,770 live births over the 15-year study period, 5900 individuals with one of the five selected common aneuploidies were identified in the HIRA database, corresponding to an overall claims-based diagnostic registration ratio of 105.6 per 100,000 live births. Down syndrome was the most frequently registered disorder, accounting for 59.51% of the cases, followed by Turner syndrome (19.56%), Klinefelter syndrome (14.76%), Edwards syndrome (4.63%), and Patau syndrome (1.54%). The corresponding claims-based diagnostic registration ratios were 62.8, 20.7, 15.6, 4.9, and 1.6 per 100,000 live births, respectively. Edwards and Patau syndromes had the highest clinical burden, with discharge-recorded in-hospital mortality of 34.07% (95% CI, 28.46–40.02) and 32.97% (95% CI, 23.47–43.61), respectively, and the highest median first-year healthcare expenditures of 17,394,435 KRW (Q1–Q3, 1,087,560–61,040,440) and 7,478,665 KRW (Q1–Q3, 510,510–37,524,080), respectively. The prevalence of CHD ranged from 60.7% to 70.3% in Down, Edwards, and Patau syndromes and was approximately 11% in Turner and Klinefelter syndromes. Conclusions: This nationwide claims-based study demonstrated distinct diagnostic registration patterns and outcome disparities among the selected common aneuploidies in Korean children. These findings support the need for disorder-specific clinical pathways, integrated national surveillance, and targeted supportive care to address the substantial clinical and economic burdens.