Other albinism classes are: OCA2 caused by deletion or loss of activity of the melanosomal P-protein (OCA2 gene); OCA3 attributable to mutations in TYRP1; OCA4 due to loss of SLC45A2; and OCA5 which is linked to chromosome 4q24, with the responsible gene yet to be characterized. Here, SLC45A2 is linked to albinism.