SET domain containing 5 is a protein that in humans is encoded by the SETD5 gene.
It is a member of the histone lysine methyltransferase family.
Overexpression of SETD5 is associated positively with progression of breast cancer.
Mutations in SETD5 are associated with a rare developmental disorder termed autosomal dominant mental retardation-23 (MRD23, MIM#615761). MRD23 is mainly characterized by variable congenital defects and dysmorphic facies. Clinical features include developmental delay, intellectual disability, chewing abnormalities, hypospadias, and cryptorchidism in males in association with craniofacial dysmorphisms.