Chromosome Analysis and AFP with Reflex to AchE, Fetal Hgb, and Oligo‑SNP
Also known as: Amnio, SNP array, ClariSure®, Karyotype, Prenatal
Use
Testing determines chromosomal status of the fetus. Numerical and structural chromosomal abnormalities can be diagnosed. Sex and the presence of more than one cell line (mosaicism) can also be determined. Indications include diagnosis of chromosome abnormalities in fetuses of women who are of advanced maternal age; had a previous child with a chromosome abnormality; parental carrier of a balanced translocation, inversion or marker chromosome; parental mosaicism and follow‑up for abnormal maternal serum alpha fetoprotein or maternal screening results. Chromosomal Microarray, Prenatal, ClariSure® Oligo‑SNP – This assay may be useful for further investigation on fetuses with abnormal ultrasound findings indicating congenital malformation; further definition of an imbalanced cytogenetic abnormality; further investigation on equivocal cytogenetic findings; attempt at characterization of supernumerary marker chromosome; follow‑up to a documented chromosome abnormality or genomic alteration in a sibling or a parent; family history of a previous child with mental retardation and/or phenotypic abnormalities.
Special Instructions
Physician attestation of informed consent is required if ordering facility is located in AK, AZ, DE, FL, GA, MA, MN, NV, NH, NJ, NM, NY, OR, SD or VT or if test is performed in MA. Signed informed consent is a requirement. Amniotic fluid kit and handling instruction available upon request. Patient’s age, gestational age, and indication(s) for testing are necessary; please submit completed cytogenetics requisition form with information. Do not split even if AFP requested. Send all tubes to lab (supernatant for AFP will be split by cytogenetics lab). Specimen viability decreases during transit. Send specimen to testing lab for viability determination.
Limitations
If Chromosome Analysis, Amniotic Fluid is normal, then Chromosomal Microarray, Prenatal, ClariSure® Oligo‑SNP will be performed at an additional charge (CPT code(s): 81229). If AFP MoM is equal to or greater than 2.0, then Acetylcholinesterase and Fetal Hemoglobin will be performed at an additional charge (CPT code(s): 82664, 83033). The assay cannot detect 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.
Methodology
Chromosomal / Cytogenetics (Karyotype)
Biomarkers
Result Turnaround Time
6-8 days
Related Documents
For more information, please review the documents below
Specimen
Other
Volume
30 mL
Minimum Volume
10 mL
Container
sterile tube
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Preferred |
| Refrigerated | Acceptable |
| Frozen | Unacceptable |