Copy-number variatiants (CNVs) are structural variations of the chromosomes. These alterations result in the body's cells having a difference in the number of copies of one (or more) sections of DNA.
Copy number variations may result in a gain (duplication) or loss (deletion) of the DNA. Extra or missing genetic material can impact an individual's health, learning and behavior. How an individual is affected varies based on where this change occurs in the DNA, how large the change is, and how important the genes involved in the change are to growth and development.
Back to: Genetics FAQ
Next Section: What kinds of genetic changes can happen in just one gene?