GLT8D2 (glycosyltransferase 8 domain-containing protein 2), also known as GALA4A, is a 349 amino acid single-pass type II membrane protein. A member of the glycosyltransferase 8 family, GLT8D2 is encoded by a gene that maps to human chromosome 12q23.3. Encoding over 1,100 genes within 132 million base pairs, chromosome 12 makes up about 4.5% of the human genome. A number of skeletal deformities are linked to chromosome 12, including hypochondrogenesis, achondrogenesis, Noonan syndrome, Kniest dysplasia and trisomy 12p. Chromosome 12 is also home to a homeobox gene cluster, which encodes crucial transcription factors for morphogenesis, as well as the natural killer complex gene cluster, which encodes C-type lectin proteins that mediate the NK cell response to MHC I interaction.