Question 2. A patient has a personal or family history of a chromosome abnormality. Prenatal chromosome analysis was reported as normal. Does this result guarantee the fetus does not have the familial chromosome abnormality?

No, please contact Quest Genomics Client Services at 1.866.GENE.INFO (1.866.436.3463) to talk to a genetic science specialist about appropriate testing based on the specific genetic abnormality in the family history.

Question 3. Which chromosome abnormalities does this assay rule out?

This assay rules out Trisomies such as Down syndrome, trisomy 18, and trisomy 13 Sex chromosome abnormalities, including Turner syndrome and Klinefelter syndrome Most rearrangements, including Robertsonian translocations and inversions Marker chromosomes Mosaicism above 14% (at a 95% confidence level); if mosaicism is suspected, before sending the specimen, please call Quest Genomics Client Services at 1.866.GENE.INFO (1.866.436.3463) to talk with a genetic science specialist to best assure the correct tests are ordered.

Question 4. Which disorders cannot be detected by this assay?

This assay cannot detect Most microdeletion syndromes, including DiGeorge, Prader-Willi, Angelman, Williams, and Smith Magenis Mosaicism below 14% (at a 95% confidence level) Fragile X syndrome Single-gene disorders, including cystic fibrosis, Marfan syndrome, and neurofibromatosis Disorders associated with small cryptic (not microscopically visible) gains or losses or genetic material If a microdeletion syndrome or mosaicism is suspected, before sending the specimen please call Quest Genomics Client Services at 1.866.GENE.INFO (1.866.436.3463) to talk with a genetic science specialist to best assure the correct tests are ordered.

Chromosome Analysis Chorionic Villus Sample

Test code(s) 14592

Yes, other studies may be appropriate. Chromosomal Microarray, Prenatal, ClariSure^®Oligo-SNP (test code 90927) detects aneuploidies, deletions and duplications below the resolution of chromosome analysis, and long continuous regions of homozygosity. Please contact Quest Genomics Client Services at 1.866.GENE.INFO (1.866.436.3463) to talk to a genetic science specialist and for information on adding this or other available tests.

This assay rules out

Trisomies such as Down syndrome, trisomy 18, and trisomy 13
Sex chromosome abnormalities, including Turner syndrome and Klinefelter syndrome
Most rearrangements, including Robertsonian translocations and inversions
Marker chromosomes
Mosaicism above 14% (at a 95% confidence level); if mosaicism is suspected, before sending the specimen, please call Quest Genomics Client Services at 1.866.GENE.INFO (1.866.436.3463) to talk with a genetic science specialist to best assure the correct tests are ordered.

This assay cannot detect

Most microdeletion syndromes, including DiGeorge, Prader-Willi, Angelman, Williams, and Smith Magenis
Mosaicism below 14% (at a 95% confidence level)
Fragile X syndrome
Single-gene disorders, including cystic fibrosis, Marfan syndrome, and neurofibromatosis
Disorders associated with small cryptic (not microscopically visible) gains or losses or genetic material

If a microdeletion syndrome or mosaicism is suspected, before sending the specimen please call Quest Genomics Client Services at 1.866.GENE.INFO (1.866.436.3463) to talk with a genetic science specialist to best assure the correct tests are ordered.

Yes. Maternal Cell Contamination Study, STR Analysis (test code 10262) can be used to test for maternal cell contamination. A maternal blood specimen is needed for this test. Please call Quest Genomics Client Services at 866-GENE-INFO to add a MCC to an existing result.

This FAQ is provided for informational purposes only and is not intended as medical advice. A physician’s test selection and interpretation, diagnosis, and patient management decisions should be based on the physician’s education, clinical expertise, and assessment of the patient.

Document FAQS.76 Version: 2

Version 2 effective 12/01/2023 to present

Version 1 effective 05/21/2015 to 12/01/2023

Version 0 effective 09/12/2012 to 05/20/2015

Chromosome Analysis, Chorionic Villus Sample

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Chromosome Analysis, Chorionic Villus Sample

add Question 1. Multiple fetal anomalies were detected on ultrasound, but the chromosome analysis was normal. Can further genetic studies be done to evaluate the fetal anomalies?

add Question 2. A patient has a personal or family history of a chromosome abnormality. Prenatal chromosome analysis was reported as normal. Does this result guarantee the fetus does not have the familial chromosome abnormality?

add Question 3. Which chromosome abnormalities does this assay rule out?

add Question 4. Which disorders cannot be detected by this assay?

add Question 5. The report indicates that maternal cell contamination (MCC) cannot be ruled out. Can a test be done to evaluate for MCC?

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