Chromosome 18 (human)

Chromosome 18 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 18 spans about 76 million base pairs (the building material of DNA) and represents about 2.5 percent of the total DNA in cells.

Identifying genes on each chromosome is an active area of genetic research. Because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies. Chromosome 18 likely contains between 300 and 400 genes.

Genes
The following are some of the genes located on chromosome 18:
 * FECH: ferrochelatase (protoporphyria)
 * NPC1: Niemann-Pick disease, type C1
 * SMAD4: SMAD, mothers against DPP homolog 4 (Drosophila)

Diseases
The following diseases are some of those related to genes on chromosome 18:
 * erythropoietic protoporphyria
 * hereditary hemorrhagic telangiectasia
 * Niemann-Pick disease
 * porphyria