Prenatal diagnosis of copy number changes (gains or losses) across the entire genome
Determining the size, precise breakpoints, gene content, and any unappreciated complexity of abnormalities detected by other methods such as conventional chromosome and FISH studies
Determining if apparently balanced abnormalities identified by previous conventional chromosome studies have cryptic imbalances, since a proportion of such rearrangements that appear balanced at the resolution of a chromosome study are actually unbalanced when analyzed by higher-resolution chromosomal microarray
Assessing regions of homozygosity related to uniparental disomy or identity by descent
A maternal blood sample is requested when ordering this test (see PPAP / Parental Sample Prep for Prenatal Microarray Testing); the PPAP test must be ordered under a different order number than the prenatal specimen.
Maternal cell contamination (MCC) testing will be performed at no additional charge on the maternal blood and fetal tissue to rule out the presence of maternal cells in the product of conception sample.
A paternal blood sample is desired but not required (see PPAP / Parental Sample Prep for Prenatal Microarray Testing).
If an insufficient sample is received or MCC is identified in the prenatal sample, microarray testing will be performed on cultured material.
Portions of the specimen may be used for other tests such as measuring markers for neural tube defects (eg, AFPA / Alpha-Fetoprotein, Amniotic Fluid), molecular genetic testing, biochemical testing, and chromosome and FISH testing (including CHRAF / Chromosome Analysis, Amniotic Fluid; CHRCV / Chromosome Analysis, Chorionic Villus Sampling; and PADF / Prenatal Aneuploidy Detection, FISH).
The following algorithms are available in Special Instructions:
-Prenatal Aneuploidy Screening and Diagnostic Testing Options
-High-Risk Pregnancy Based on Abnormal Fetal Malformations: Laboratory Testing Algorithm
