For many years, seven subtypes of OCA, caused by a mutation in different genes, were known, namely, OCA1 (TYR), OCA2 (OCA2/formerP gene), OCA3 (TYRP1), OCA4 (SLC45A2), OCA5 (OCA5), OCA6 (SLC24A5), and OCA7 (C10ORF11) (OMIM®, An Online Catalog of Human Genes and Genetic Disorders; http://www.omim.org; accessed on 20 January 2022). Here, TYR is linked to hereditary disease.