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Chromosomal microarray analysis (CMA) for detecting copy number variations (CNVs) in chromosomal material

Published: August 9, 2026Updated: August 16, 2026

This test checks for changes in the number of copies of specific genes or chromosome regions, which may be linked to genetic conditions or developmental concerns.

Quick summary

["CMA helps identify genetic differences that could influence health or development."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
21771-1
Short code
Chr 21 Ts Bld/T Ql
Synonyms
Chr 21 Ts Bld/T Ql
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
cytogenetics
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What This Test Measures

CMA examines DNA from your blood or other sample to detect small changes in chromosome structure or quantity. It looks for gains or losses of genetic material that might not be visible with traditional chromosome testing.

How the Test Works

Your sample is analyzed using advanced technology that compares genetic material against a reference database. This helps pinpoint any unusual patterns that could indicate genetic conditions.

When You Might Need This Test

CMA is often recommended for individuals with unexplained developmental delays, intellectual disabilities, or physical features that suggest a genetic cause. It may also be used in prenatal testing for certain high-risk pregnancies.

Common Conditions Linked to Findings

While CMA can detect a wide range of genetic variations, some conditions commonly associated with findings include Down syndrome (trisomy 21), Prader-Willi syndrome, Angelman syndrome, and other chromosomal imbalances.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CMA for chromosomal analysis

Frequently asked questions

Why was this test ordered?
Your healthcare provider may have recommended this test based on your medical history, symptoms, or family history. It helps identify genetic factors that could explain health concerns or guide treatment decisions.
What does a positive result mean?
A positive result means the test found genetic changes that may contribute to your health issues. These findings can help explain symptoms, inform diagnosis, and direct further testing or management plans.
How long will it take to get results?
Results are typically available within 2 to 4 weeks, depending on the lab and complexity of the test. Follow-up with your healthcare provider is important to discuss findings and next steps.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy