Gene dosage

Gene dosage is the number of copies of a particular gene present in a genome. Gene dosage is known to be related to the amount of gene product the cell is able to express, however, amount of gene product produced in a cell is more commonly dependent on regulation of gene expression. Nonetheless,changes in gene dosage (copy number variations) due to gene insertions or deletions can have significant phenotypic consequences.

Most genes found in the cell are expressed as autosomal genes (see autosome) and are found in two copies, alterations to this two-copy gene dosage is significantly associated with quantitative or qualitative phenotype traits and is linked to many genetic health problems such as those associated with Down Syndrome. In Down Syndrome, the gene expression on chromosome 21 has increased 50%, and this results in significant health and mental disabilities (1 in 800 human live births have Down Syndrome).

See also

• Copy-number variation
• Dosage compensation
• Genetic association
• Polyploidy, Aneuploidy