Chromosomal Microarray (CMA) Test - Mapmygenome

High-resolution, genome-wide mapping using industry-leading Illumina® SNP microarray technology to detect copy number variations and chromosomal anomalies.

Overview

The Chromosomal Microarray (CMA) test is an advanced, high-resolution genomic assay designed to detect microscopic and sub-microscopic chromosomal abnormalities. Powered by Illumina’s state-of-the-art SNP microarray platform, this test acts as a first-tier diagnostic tool that scans the entire genome to identify Copy Number Variants (CNVs)—including microdeletions and microduplications—as well as copy-neutral genomic variations that traditional karyotyping (G-banding) cannot detect.

Whether evaluating neurodevelopmental disorders in children or investigating complex reproductive challenges, our Illumina-powered CMA provides clinicians and families with precise, actionable diagnostic insights.

The Technology: Illumina® SNP Microarray

Our laboratory utilizes Illumina’s high-density Single Nucleotide Polymorphism (SNP) array technology. Unlike older array-CGH technologies that only measure relative DNA gains and losses, Illumina’s SNP-based architecture tracks both signal intensity (to detect deletions and duplications) and allelic composition (genotyping).

This dual-capability allows our platform to detect:

• Copy Number Variants (CNVs): Microdeletions and microduplications.

• Absence of Heterozygosity (AOH) / Loss of Heterozygosity (LOH): Regions of the genome that are identical by descent, which is crucial for identifying risks of autosomal recessive disorders, consanguinity, and conditions caused by Uniparental Disomy (UPD) (e.g., Prader-Willi or Angelman syndromes).

Clinical Indications: Who Should Get Tested?

In accordance with global medical guidelines (including ACMG and ACOG), Illumina CMA testing is recommended as a first-tier test for:

Pediatric & Postnatal Evaluation:

• Unexplained Developmental Delay (DD) or Intellectual Disability (ID)

• Autism Spectrum Disorders (ASD)

• Multiple Congenital Anomalies (MCA) or dysmorphic features

• Unexplained seizure disorders or early-onset neurological conditions

Reproductive & Prenatal Evaluation:

• High-risk pregnancies presenting with structural anomalies on fetal ultrasound

• Evaluation of recurrent pregnancy loss, stillbirth, or spontaneous abortion (analysis of Products of Conception)

• Couples dealing with unexplained infertility or repeated IVF failures

Key Benefits of Our Illumina CMA Test

• Unmatched Resolution: Detects sub-microscopic genetic anomalies at a resolution up to 100 times higher than conventional chromosome analysis.

• Dual CNV & SNP Detection: Thanks to Illumina's bead-array architecture, we can flag copy-neutral structural anomalies (like UPD and AOH) that standard CGH arrays miss.

• Comprehensive Genome Mapping: Screens across the entire genome in a single assay, eliminating the need for multiple sequential single-gene tests.

• End the "Diagnostic Odyssey": A definitive molecular diagnosis allows clinicians to initiate tailored medical management, guide early therapeutic interventions, and calculate precise recurrence risks for future pregnancies.

Test Limitations (What CMA Does Not Detect)

While Illumina SNP microarray technology is highly robust, it has specific inherent limitations:

• Cannot detect completely balanced chromosomal rearrangements (e.g., balanced reciprocal translocations or inversions) where there is no net loss or gain of genetic material.

• Cannot detect Single Nucleotide Variants (SNVs) or small indels within individual genes (which require Whole Exome or Genome Sequencing).

• May not detect very low-level tissue mosaicism (typically below 10–20%).

Sample Requirements & Testing Process

• Sample Type: Peripheral Blood (EDTA tube) for postnatal testing. Amniotic fluid, Chorionic Villus Sampling (CVS), or Products of Conception (POC) for prenatal/reproductive evaluations.

• Turnaround Time (TAT): Typically 2 to 3 weeks.

• Expert Support: Every test includes access to our certified genetic counselors to assist clinicians and patients with pre-test counseling, interpretation of complex variants (including Variants of Uncertain Significance - VUS), and post-test medical planning.