GSTM1 and Schnyder corneal dystrophy: HBB molecular analysis identified 8 individuals with Hb SS SCD (0.94%) (mean age 7.27 years), 59 individuals with HbSA (6.95 %) (mean age 6.05 years), 2 individuals with HbAC (0.23%) (mean age 2 years), 1 individual bearer of a sequence variant samesense (0.19 %) (8 years).