Chromosomal Microarray: aCGH and SNP Testing


Chromosomal microarray using array comparative genomic hybridization with single nucleotide polymorphism (array CGH and SNP) testing is a comprehensive analysis to examine the entire genome for deletions and duplications, as well as copy neutral changes that may be clinically significant. We offer two array options:

  • Prenatal chromosomal microarray: Recommended for routine prenatal cases, including indications of parental concern, advanced maternal age, and increased risk for a chromosomal abnormality by family history, non-invasive prenatal testing (NIPT), or maternal serum screening
  • High resolution chromosomal microarray: Recommended for all postnatal cases (pediatric, adults, and products of conception), as well as prenatal cases with ultrasound findings. This array has an increased rate of variants of uncertain clinical significance (VUS) due to higher resolution

The microarray that we offer utilizes ~180,000 CGH and SNP probes covering the entire genome with enriched coverage in regions known to be involved in submicroscopic chromosome abnormalities. This array yields high-resolution detection of deletions and duplications with aberrations less than 1 kb possible in known genomic loci. The additional SNP probes allow for the simultaneous detection of copy neutral absence of heterozygosity (AOH), which can identify autosomal recessive disease regions and/or be indicative of uniparental disomy (UPD). All abnormal copy number aberrations are confirmed in-house using fluorescence in situ hybridization (FISH).

CGH and SNP testing may be used to diagnose children with developmental delay, intellectual disability, and/or multiple congenital anomalies, identify a specific genetic etiology in children diagnosed with Autism Spectrum Disorder, identify copy neutral AOH indicative of autosomal recessive disorders, aid in diagnosing a child or adult that presents with non-classical features of a genetic syndrome, aid in diagnosing a fetus presenting with ultrasound abnormalities, and diagnose UPD. It can also provide higher resolution than conventional karyotyping to identify pathogenic deletions and duplications, and be used to detect chromosomal aneuploidies (eg, trisomy 21 and 45, X) or unbalanced rearrangements that are de novo or associated with parental balanced structural aberrations.


Specimen Requirements

Prenatal

  • Amniotic fluid: Minimum 10-15 mL direct fluid in a sterile conical centrifuge tube, or
  • Chorionic villus sampling (CVS): 5-10 mg chorionic villi in sterile saline, or
  • Two confluent T-25 flasks

  • Additionally, please send:
  • Maternal blood: 5-10 mL in EDTA tube (lavender top) in case maternal confirmation studies are necessary or if parental specimens are needed for testing and result interpretation
  • Paternal blood: 5-10 mL in EDTA tube (lavender top) in case parental specimens are needed for testing and result interpretation

Postnatal

  • Whole blood: Minimum 5-10 mL in ETDA tube (lavender top)
  • Products of conception: Skin, cord, or villi in sterile saline

Ordering Information

Shipping

  • Ship at room temperature or refrigerated

Turnaround Time

  • 7-14 days


Resources

Prenatal Test Requisition with Natera NIPT
Prenatal Test Requisition with Sequenom NIPT
General Test Requisition
Chromosomal Microarray and Microdeletion FISH Panel Information Sheet