Based on this analysis, serum miR-21 (OR: 17.246; 95% CI: 3.334–89.218; P = 0.001), increased serum Cys C (OR: 29.858; 95% CI: 9.588–92.983; P < 0.001), serum KIM-1 (OR: 4.041; 95% CI: 1.204–13.568; P = 0.024), hyperlipidaemia (OR: 8.415; 95% CI: 1.764–40.143; P = 0.008) and EF (OR: 0.940; 95% CI: 0.901–0.981; P = 0.004) were independent influencing factors for the occurrence of CRS (Table 3). The gene discussed is HAVCR1; the disease is congenital rubella syndrome.