Chromosomal Microarray
About this test
A chromosomal microarray, also called a microarray or array, helps to find out if you or your child has a health or learning concern that may have a genetic cause.
What are chromosomes?
Each cell in your body has the genetic instructions that tell your body how to develop and function. The genetic instructions are packaged into structures called chromosomes. You have 2 copies of most chromosomes. One copy comes from the egg and one from the sperm that formed you. Because chromosomes contain your genetic instructions, the full set of chromosomes is important for growth and development.
What is an array?
An array is a test that looks for pieces of chromosomes that are missing, or pieces that are extra. A missing piece of chromosome is called a deletion. An extra piece of chromosome is called a duplication. These chromosome differences can sometimes cause health or learning concerns.
Chromosome differences are not caused by something a person or parent did or did not do. Sometimes, a chromosome difference can be a new, random change that did not come from a parent. In other cases, they can be passed down from a parent to a child.
To do an array, a lab will take a sample of blood. In Alberta, there is no cost to you for this test.
The results may take several months to come back. Ask your healthcare provider how you will learn about the results.
What type of results could I get?
- Positive result: A positive result means that the array found a genetic cause for your or your child’s health or learning concerns. Knowing the genetic cause of these concerns can give you and your healthcare team helpful information. Testing the biological parents can also show how the condition may be passed down in a family.
- Negative or uninformative result: A negative or uninformative result means that the array did not find a genetic cause for your or your child’s health or learning concerns. But an array cannot check for every possible genetic condition. In some cases, your healthcare team may suggest a more detailed test.
- Uncertain result: An uncertain result means that the array found a difference, but it is not well-understood. The difference may or may not explain the health or learning concerns. Your healthcare team will talk with you about next steps to try to better understand this result. Sometimes biological parents or other family members may be asked to provide a blood sample for more testing.
- Incidental finding: An incidental finding means that the array found a genetic condition, but it is not related to your current concern. This can happen because the array looks at all of your chromosomes. This can be surprising to learn about. Although an incidental finding does not explain your current health or learning concerns, it may still be medically important for you and your family.
To see this information online and learn more, visit MyHealth.Alberta.ca/health/aftercareinformation/pages/conditions.aspx?hwid=custom.ab_chromosomal_microarray_inst.
Related to Chromosomal Microarray
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Current as of: November 27, 2023
Author: Clinical and Metabolic Genetics Program, Alberta Health Services
This material is not a substitute for the advice of a qualified health professional. This material is intended for general information only and is provided on an "as is", "where is" basis. Although reasonable efforts were made to confirm the accuracy of the information, Alberta Health Services does not make any representation or warranty, express, implied or statutory, as to the accuracy, reliability, completeness, applicability or fitness for a particular purpose of such information. Alberta Health Services expressly disclaims all liability for the use of these materials, and for any claims, actions, demands or suits arising from such use.
