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Chromosomal Microarray, Prenatal, ClariSure® Oligo-SNP

Test code(s) 90927

This test may be useful for investigation of fetuses with abnormal results on prenatal ultrasound or other prenatal screens; for definition of unbalanced cytogenetic abnormalities; and for follow-up to a documented chromosome or microarray abnormality in a family member. Chromosomal microarray (CMA) may also be used as follow-up if there is a family history of developmental delay, intellectual disability, and/or congenital malformations in a previous child. Per the American College of Obstetricians and Gynecologists, CMA may be offered to patients who prefer comprehensive prenatal detection of as many chromosomal abnormalities as possible.1

CMA detects chromosomal deletions and duplications, including those that are below the resolution of routine chromosome analysis (karyotyping). It also detects long continuous regions of homozygosity. Unlike routine chromosome analysis, CMA does not detect balanced rearrangements.

This assay can detect

  • Trisomies, such as Down syndrome, trisomy 18, trisomy 13.
  • Sex chromosome abnormalities, such as Turner and Klinefelter syndromes.
  • Most marker chromosomes.
  • Small deletions/duplications throughout the genome that are within the resolution of the assay.
    - For more information, please call 1.866.GENE.INFO to speak with a genetic counselor.
  • Segments of homozygosity that may represent a risk for a recessive Mendelian disorder or uniparental disomy. 

This assay cannot detect

  • Low-level mosaicism.
  • Balanced rearrangements, including Robertsonian translocations, reciprocal translocations, and inversions.
  • Fragile X syndrome.
  • Single gene disorders, such as Marfan syndrome, cystic fibrosis, neurofibromatosis, etc.
  • Small deletions/duplications below the resolution of this assay.
    - For more information, please call 1.866.GENE.INFO to speak with a genetic counselor.
  • Small segments of homozygosity that are outside the threshold set by the lab (approximately 10 Mb).

We will not report benign or likely benign findings.

For more information or to discuss a specific case with a Quest Diagnostics genetic counselor, please call Quest Genomics Client Services at 1.866.GENE.INFO.


  1. Rose NC, Kaimal AJ, Dugoff L, et al. Screening for fetal chromosomal abnormalities: ACOG Practice Bulletin, Number 226. Obstet Gynecol. 2020;136(4):e48-e69. doi:10.1097/AOG.0000000000004084


This FAQ is provided for informational purposes only and is not intended as medical advice. A clinician’s test selection and interpretation, diagnosis, and patient management decisions should be based on his/her education, clinical expertise, and assessment of the patient.

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Version0: Effective 01/18/2021to present