Prenatal Microarray

Test Information

This whole genome SNP microarray detects CNVs and allows for the analysis of loss of heterozygosity which can be useful in identifying uniparental disomy (UPD). Prenatal microarray can be used in cases of fetal anomalies and/or a suspected deletion/duplication syndrome.

Turnaround Time

2 weeks from sample receipt. Cell culture, if needed, takes 1-4 weeks and may lengthen turnaround time.

CPT Code(s)




Clinical Information

This thorough analysis of regions throughout the genome may identify the causes of numerous genetic conditions and cases of unexplained intellectual disabilities or other anomalies. This SNP array also allows for the analysis of loss of heterozygosity which can be useful in identifying uniparental disomy (UPD) as well as autozygosity (identity by descent).

This array features over 1.8 million markers of genetic variation. There are over 946,000 nonpolymorphic probes for copy number detection including 202K probes for targeting 5677 known CNV regions as well as 744K probes tiled evenly along the genome. In addition, there are more than 906,600 SNPs comprise of an unbiased selection of 482,000 SNPs and specific selection of 424,000 SNPs.

Areas of homozygosity (AOH) or loss of heterozygosity (LOH) will be reported

When the total autosomal homozyogosity is >10%
When an isolated LOH/AOH of at least 10 Mb is found on imprinted chromosome or when an isolated LOH/AOH of at least 15 Mb is found on a non-imprinted chromosome.

The following findings WILL NOT be reported for prenatal specimens:

CNVs associated with adult onset disorders
This group of specific CNVs:
Deletions associated with infertility involving the AZF loci in males
Deletions and duplications of the BP1-BP2 region at 15q11.2
Duplications of the NPHP1 locus at 2q13
Focal duplications involving the STS gene in males and females
Duplications involving the PAR1/SHOX region on Xp/Yp
Duplications of the recurrent 16p13.11 region
Deletions/duplications of 17p12/PMP22 associated with HNLPP and Charcot-Marie-Tooth, respectively


Prenatal microarray may be indicated in the presence of multiple fetal anomalies or other unexplained ultrasound findings.

Specimen Requirements

This test can be performed from direct amniotic fluid or on cultured amniocytes. If sending direct fluid for microarray only, 10-20 ml of amniotic fluid is requested. Chromosomes and FISH will require an additional 10-15 ml of fluid. If sending cultured flasks, 2x T25 confluent flasks are required.

Parental samples are required to accompany prenatal specimen. 4-5 ml of peripheral blood should be collected on each parent in an EDTA (lavender top) tube.

Transport Instructions

The specimen should be kept at room temperature and delivered via overnight shipping. Do not freeze.

Prenatal Testing Information

Prenatal diagnosis is available for cases of congenital anomalies or other clinical findings suggestive of aneuploidy.

Have Questions? Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Kellie Walden, MS, CGC

Cytogenetic Testing, Microarray, Prenatal Studies
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