Chromosome Analysis, Amniotic Fluid

Yes, other studies may be appropriate. There are many causes for fetal anomalies, some of which are genetic. In the absence of clinical suspicion for a specific genetic disorder, a microarray analysis may be performed to detect subtle deletions and duplications (Chromosomal Microarray, Prenatal, ClariSure^® Oligo-SNP, test code 90927).

If clinical suspicion exists for a specific disorder, other genetic testing may be available. Please contact Quest Genomics Client Services at 866-GENE-INFO (866-436-3463) to discuss the case with a genomic science specialist and for information on additional testing.

No. Please call Quest Genomics Client Services at 866-GENE-INFO (866-436-3463) to discuss this situation with a genomic science specialist. The specialist needs to know the specific genetic abnormality in the family, so they can determine whether the test’s resolution was sufficient to detect the abnormality. 

This assay can detect the following:

• Trisomies such as trisomy 21 (Down syndrome), trisomy 18, and trisomy 13
• Sex chromosome abnormalities such as Turner syndrome (45,X) and Klinefelter syndrome (47,XXY)
• Most rearrangements, including Robertsonian translocations and inversions
• Marker chromosomes
• Mosaicism at or above 14% (at a 95% confidence level)
• Most microscopically visible structural abnormalities

This assay cannot detect the following:

• Subtle rearrangements, microduplications, and most microdeletion syndromes, such as DiGeorge, Prader-Willi, Angelman, Williams, and Smith-Magenis syndromes
• Mosaicism below 14% (at a 95% confidence level)
• Single-gene disorders, such as fragile X syndrome, cystic fibrosis, Marfan syndrome, and neurofibromatosis

Nor can this assay detect neural tube defects, abdominal wall defects, or other birth defects associated with an elevated maternal serum alpha-fetoprotein. To test for these defects, consider ordering Alpha-Fetoprotein, Amniotic Fluid with Reflex to AchE and Fetal Hgb (test code 232).

Please contact Quest Genomics Client Services at 866-GENE-INFO for information on adding this test to a prenatal sample. 

Yes. The Maternal Cell Contamination Study, STR Analysis test (test code 10262) can be performed if a maternal blood sample is submitted. If considering adding MCC studies to a completed prenatal case, please call Quest Genomics Client Services at 866-GENE-INFO (866-436-3463) to speak with a genomic science specialist.