Chromosome 21

The significance of human chromosome 21 is that the trisomy of human chromosome 21 causes Down syndrome in children. There are about 235 protein-coding genes on chromosome 21. Mutations like translocation in human chromosome 21 cause different conditions such as partial monosomy 21, core binding factor acute myeloid leukemia, ring chromosome 21, and other types of cancers such as acute lymphoblastic leukemia. Mutation in the DSCAM gene causes mental retardation and facial deformities in down syndrome. The human chromosome 21 also comprises the APP gene, where the expression of the gene causes Alzheimer's disease. The genes that are involved in causing Down syndrome and Alzheimer's diseases are also involved in cancer. This chapter discusses 63 genes of human chromosome 21 that are involved in different types of cancer.