Chromosomal Microarray (CMA) is an advanced genetic test used to identify small gains or losses of chromosomal material that may not be detected through conventional chromosome analysis. It is commonly recommended when a child or adult has developmental delay, intellectual disability, congenital abnormalities, autism spectrum disorder, or unexplained growth or learning concerns.
When Is CMA Testing Recommended?
A healthcare professional or genetic counsellor may recommend a CMA test when there is a suspected chromosomal condition or when the underlying cause of developmental or congenital problems is unclear. The test can help identify clinically significant copy number changes and provide useful information for further medical evaluation and genetic counselling.
How Does Chromosomal Microarray Testing Work?
CMA is generally performed using a blood sample, although the appropriate sample type can depend on the clinical situation. The laboratory examines the patient's DNA for specific copy number variations (CNVs), including deletions and duplications of chromosomal regions. Results should be interpreted alongside the patient's medical history and clinical findings.
Understanding Your Results
A CMA result may be reported as normal, abnormal, or uncertain. An abnormal finding does not always explain every health concern, while a variant of uncertain significance may require additional assessment or family testing. Your doctor or genetic counsellor can explain what the result means for your individual situation.