Granular corneal dystrophy type 2 (GCD2), also known as Avellino corneal dystrophy, is an autosomal dominant disorder caused by a mutation in codon 124 of the transforming growth factor-beta-induced (TGFBI) gene, in which histidine replaces arginine (R124H). Here, TGFBI is linked to granular corneal dystrophy type II.