- Rapid Aneuploidy FISH is used to detect approximately 99% of +13, +18, +21, and aneuploidies of X & Y. This test is not designed to detect structural chromosome abnormalities and inconclusive results may occur if mosaicism is present.
- Constitutional (Targeted) FISH is used to analyze a particular region of interest within a single chromosome. Alternate testing may be appropriate, as many of the microdeletions/microduplication conditions detected by targeted FISH are also identified using the Prenatal Microarray.
Test details and complementary testing
- This test analyzes fetal cells during a pregnancy. Postnatal testing on maternal, paternal, or newborn blood after delivery, including Postnatal Chromosome Analysis, Postnatal FISH, or Postnatal Microarray, must be ordered separately.
- Prenatal Chromosome Analysis for confirmation and clarification of trisomy, translocation, or mosaicism of 13, 18, 21 or sex chromosome differences is required in conjunction with Aneuploidy FISH.
- Prenatal Chromosome Analysis is recommended in conjunction with any Constitutional (Targeted) FISH.
- In conjunction with Chromosome Analysis, FISH, and/or Microarray, Amniotic Fluid AFP (AF-AFP) can be ordered on amniotic fluid samples with a gestational age of 22 weeks 6 days or less. (AChE should be ordered, instead of AF-AFP, if gestational age is 23 weeks or greater). In most situations if AF-AFP is positive, AChE will be completed. These non-genetic send-out tests can be ordered on our laboratory’s test request form, but are performed, reported, and billed by UNMC Regional Pathology Services and questions for these tests should be directed to their laboratory by calling 402-559-6420.
- If single gene testing is considered for a familial genetic condition or abnormal ultrasound findings, contact a laboratory genetic counselor for coordination of testing prior to sending the sample.