The Human Genome Project: Genes on Human Chromosome 17 The location of genes is designated by an established labeling system for chromosomes. Here is a drawing of human chromosome 17 showing its characteristic major banding pattern as it appears after staining. By convention, chromosomes are drawn with the short arm on the top labeled p (for petit) and the long arm on the bottom labeled q. To indicate the location of a gene on a particular chromosome, the chromosome number is followed by p or q and then a number that represents the band and sub-band. For example, 17p13.3 designates the p arm of chromosome 17, band 13, sub-band 3. In some cases only an approximate location is known so a range of numbers is given. 388 genes have been identified on human chromosome 17. The general locations of a few of these genes are shown using their standard abbreviations. Let's review the gene's exact location and a brief description of the gene's function. The gene RP13 is located at 17p13.3, and is one of several genes that affect eye development. Patients with alterations in this gene can experience a progressive visual loss with onset of night blindness between 4 and 10 years of age. The gene TP53 is located at 17p13.1. The protein encoded by this gene appears to act as the gatekeeper for the cell-cycle control system that regulates cell growth and division. Consequently, individuals with defects in this protein have an increased risk for many types of cancer. The GLUT4 gene is located at 17p13. The protein encoded by this gene is one of a family of related proteins that transports glucose into cells by facilitated diffusion. In mice, this gene is absolutely essential for sustained growth and expected longevity. The gene BLMH is located at 17q11.2, and the gene encodes an enzyme. The only known function of the enzyme encoded in this gene is the inactivation of a protein (BLM) that's toxic to the lungs. Another form of this enzyme is suspected of being involved in the development of Alzheimer's disease. The gene SLC6A4 is located at 17q11.1 to q12. There is some correlation between the alteration of this gene and personality traits, especially anxiety and depression. Recent work suggests that other changes in this gene may contribute to panic disorder. The gene KRTHA1 is located at 17q12 to q21. This region of the chromosome has a cluster of genes that encode the hard proteins, which are involved in the formation of hair and nails. The gene Gastrin is located at 17q21. Gastrin is a hormone whose main function is to stimulate secretion of hydrochloric acid (HCl) by the stomach. The gene GH1 is located at 17q22 to q24. Genetic engineering has been used to clone this growth hormone gene, which has enabled the production of growth hormone used in the treatment of pituitary dwarfism. This gene, DCP1, located at 17q23, codes for an enzyme that plays an important role in blood pressure regulation. This gene, MPO, located at 17q23.1, encodes an enzyme that is found in white blood cells and increases the ability of these cells to kill microorganisms. Individuals who do not make this enzyme are more susceptible to various Candida (yeast) infections. The information in this video represents only a small fraction of what's currently known about the human genome. Most of the information presented here was gleaned from the Online Mendelian Inheritance in Man website maintained by the National Library of Medicine. For more information or to explore other chromosomes you can start at the site http://www.ncbi.nlm.nih.gov/omim.