Huntingtin yeast partner E is a 458 amino acid single-pass membrane protein. HYPE is thought to interact with Huntingtin, a protein which induces neurodegeneration when mutated. HYPE also contains two tetratricopeptide repeats (TPR), which may be involved in protein-protein interaction. The gene that encodes HYPE is located on chromosome 12, which encodes over 1,100 genes within 132 million bases and makes up about 4.5% of the human genome. A number of skeletal deformities are linked to chromosome 12 including hypochondrogenesis, achondrogenesis and Kniest dysplasia. Chromosome 12 is also home to a homeobox gene cluster which encodes crucial transcription factors for morphogenesis, and the natural killer complex gene cluster encoding C-type lectin proteins which mediate the NK cell response to MHC I interaction. Trisomy 12p leads to facial development defects, seizure disorders and a host of other symptoms varying in severity depending on the extent of mosaicism and is most severe in cases of complete trisomy.