Reveal SNP Microarray and Abbreviated Chromosome Analysis (Amniotic Fluid)

The test allows prenatal detection of chromosomal aneuploidy, and is used to rule out tetraploidy and rearrangements not detected by array, such as balanced translocations and inversions. It also helps to clarify array abnormalities to determine if a structural rearrangement, marker, or isochromosome is present. Array can only provide copy number imbalances and cannot determine structure of an abnormality. The SNP assay will detect chromosomal imbalances that could be associated with developmental delay/congenital anomalies. It provides detection of possible uniparental disomy of any chromosome, the percent and location of homozygosity, including the degree of identity by descent.

A completed Clinical Questionnaire for SNP Microarray should accompany specimens. Call 800-345-4363 to request the appropriate form, or photocopy the form from the Genetics Appendix. Concurrent maternal contamination (MCC) studies (Maternal Cell Contamination [511402]) are  recommended. If prior NIPT studies have been performed, include copy of the report. If specimens from a twin pregnancy are submitted by request it can be reported if these are DZ or MZ twins. Gender by ultrasound is required. 

If the specimen does not meet minimum DNA quality and quantity requirements, array testing will be performed on cultured material. If cultures are needed and performed by Labcorp, additional days will be required to complete testing. A delay notification will be sent to the client if cultures are necessary.

This SNP assay does not detect balanced rearrangements, low-level mosaicism (<10%), marker chromosomes that only contain heterochromatin or tetraploidy.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

Five-cell G-Band Chromosome analysis. SNP microarray analysis is performed using the Cytoscan® HD Accel platform, which uses more than 743,130 SNP probes and 2,029,441 NPCN probes with a median spacing of 0.818 kb.