Chromosome 18

Chromosome 18 represents approximately 2.5% of the total DNA in cells.


  • autosome
  • small sized chromosome
  • about 76,000,000 base pairs
  • about 432 genes

Gene examples of chromosome 18:

The NPC1 (Niemann-Pick disease, type C1) gene encodes a protein that plays a role in the transport of cholesterol and other lipids across cell membranes. Mutations in the NPC1 gene often cause a deficiency of the NPC1 protein. As a result, the lipids in spleen, liver, lungs, bone marrow and brain accumulate to harmful amounts within the cells leading to cell death (Niemann-Pick disease).

The DYM gene encodes the protein dymeclin. Dymeclin is necessary for normal skeletal development and brain function. Mutations in the DYM gene are associated with Dyggve-Melchior-Clausen dysplasia and Smith-McCort dysplasia, which involve both skeletal defects and mental retardation.

The chromosome 18 image

The whole chromosome 18 image has a width of 3500 px and a height of 21762 px. It is too big to display here but you can download the chromosome 18 image. A 200 px wide overview of the chromosome can be seen on the right (bottom). Additionally, we show some details out of the original sized chromosome picture below.

Image details (examples):