FUCA2 and Schnyder corneal dystrophy: However, FUCA2, IL18, and SLC16A2 are unlikely to simply be genomic markers for worsening SCD because biomarkers (such as hemoglobin, hydroxyurea use, and number of transfusions) indicate that SCD severity was not different between those with and without diastolic dysfunction (E/e′ > 8.2) in both cohorts (Table 1).