Rapid Prenatal Whole Genome Chromosomal Microarray (CMA-ISCA) Test
Use
This test is designed for individuals requiring rapid chromosomal analysis during an ongoing pregnancy. Indications for this test include abnormal fetal ultrasound findings, abnormal non-invasive prenatal testing (NIPT) screening, abnormal maternal serum screening, advanced maternal age, or cases involving invasive prenatal testing. It is also used for evaluations related to family history of balanced rearrangement, stillbirth, neonatal deaths, and spontaneous pregnancy loss. The chromosomal microarray (CMA) approach is used to detect copy number variants (CNVs) associated with genomic disorders and provides higher diagnostic yield than traditional karyotyping.
Special Instructions
The test requires at least one parental specimen for quality assurance, and it is recommended to have a back-up cell culture, especially when using NGS or other prenatal testing methods. The test has a STAT priority turnaround unless otherwise indicated. Results may reveal information unrelated to the patient’s clinical features, and genetic counseling is advised both prior to testing and when interpreting results.
Limitations
CMA can only detect gross genomic copy number imbalances and long contiguous stretches of homozygosity (LCSH). It cannot detect low levels of mosaicism, balanced chromosomal rearrangements, point mutations, indels, or mitochondrial genome imbalances. Additionally, the test may miss certain forms of UPD disorders and cannot determine the origin of alterations (paternal, maternal, or de novo). Parental testing may be necessary for more comprehensive interpretation.
Methodology
Chromosomal / Cytogenetics (Microarray)
Biomarkers
Result Turnaround Time
6-10 days
Related Documents
For more information, please review the documents below
Specimen
Amniotic Fluid
Volume
Not provided
Minimum Volume
Not provided