Test Description

Chromosomal Microarray (CMA) is a high-resolution genetic test that detects submicroscopic deletions and duplications (copy number variants) across the entire genome. When performed on amniotic fluid or CVS, it provides comprehensive prenatal diagnosis for fetal structural abnormalities detected by ultrasound.

Clinical Utility

CMA offers 5-10x higher resolution than traditional karyotyping and detects clinically significant abnormalities in 6-7% of pregnancies with normal karyotype but abnormal ultrasound findings. It is now recommended as first-tier testing for pregnancies with structural anomalies.

What CMA Detects

  • Microdeletions: Small missing pieces of chromosomes (e.g., 22q11.2 deletion)
  • Microduplications: Small extra pieces of chromosomes
  • Aneuploidies: Whole chromosome abnormalities (trisomies, monosomies)
  • Uniparental disomy (UPD): Both chromosomes inherited from one parent
  • Regions of homozygosity: May suggest consanguinity or UPD

Common Syndromes Detected

DiGeorge (22q11.2)
Williams-Beuren
Prader-Willi/Angelman
Cri-du-chat
Wolf-Hirschhorn
Smith-Magenis

Technical Specifications

Our CMA platform leverages more than 750,000 markers, including approximately 550,000 unique non‑polymorphic probes for copy number variation (CNV) analysis and around 200,000 SNP probes for genotyping and allelic imbalance detection. This provides genome‑wide coverage with an average resolution of 100–200 kb across targeted regions.