When ordering chromosome analysis with reflex to microarray if chromosome analysis is normal, provide at least 30 cc of amniotic fluid or 30 mg of uncultured CVS An increase in the turnaround time and additional charges will apply for the microarray A Clinical Questionnaire for Reveal SNP Microarray - Prenatal must be completed.
Cultured CVS or amniocytes
>30 cc of amniotic fluid or 30 mg of uncultured CVS
Two confluent T-25 flasks
Discard first 2 mL of fluid aspirated to avoid maternal cell contamination. Specimen is collected in a 20 mL sterile syringe and transferred aseptically to sterile tubes
Maintain specimen at room temperature
Causes for Rejection
Quantity not sufficient for analysis (less than 10 mL of amniotic fluid or DNA quantity <20 ng/μL); bloody sample; less than 17 weeks' gestational age
This test detects chromosomal imbalance that could be associated with developmental delay/congenital anomalies. It provides detection of uniparental disomy of any chromosome, the percentage and location of homozygosity, including the degree of identity by descent.
This assay does not detect balanced rearrangements and may not detect low-level mosaicism.
Whole genome SNP-based copy-number microarray analysis targeting 2.695 million copy-number and allele-specific genome sites from uncultured cells. If DNA yield on uncultured cells is inadequate, analysis will be performed on cultured cells.
Coppinger J, Alliman S, Lamb A, et al. Whole-genome microarray analysis in prenatal specimens identifies clinically significant chromosome alterations without increase in results of unclear significance compared to targeted microarray. Prenatal Diagn. 2009 Dec; 29(12):1156-1166.PubMed 19795450
Wapner R. A multicenter, prospective, masked comparison of chromosomal microarray with standard karyotyping for routine and higher risk prenatal diagnosis. Abstract 1. Am J Ob Gyn Supplement. to Jan 2012.