Additionally, it is unclear how CHED- and FECD4- associated SLC4A11 mutations lead to two distinct corneal dystrophies, and it is unknown whether the mutations have diverging impacts on SLC4A11 function or whether the zygosity of SLC4A11 mutations is primarily what determines the type of dystrophy, CHED or FECD4. This evidence concerns the gene SLC4A11 and corneal dystrophy.