MaterniT GENOME

CPT 81420; 81422; 81479

Test Details

Use

The MaterniT Genome test provides comprehensive chromosome copy number analysis including unbalanced derivatives and, information about deletions or duplications of chromosome material 7 Mb or larger, as well as analysis of seven clinically relevant microdeletions less than 7 Mb in size.

Special Instructions

The following information must be provided with the test request form: patient's date of birth, gestational age, and additional patient demographic information: pregnancy type (singleton), donor egg status and the clinical indications (including advanced maternal age, abnormal ultrasound, history suggestive of increased risk for aneuploidy, positive serum screen, or other indications).

Limitations

While the results of these tests are highly accurate, discordant results, including inaccurate fetal sex prediction, may occur due to placental, maternal, or fetal mosaicism or neoplasm; vanishing twin; prior maternal organ transplant; or other causes. Sex chromosomal aneuploidies are not reportable for known multiple gestations. MaterniT Genome assay is not validated for multifetal gestations; multifetal samples are excluded from the resequencing pathway. These tests are screening tests and not diagnostic; they do not replace the accuracy and precision of prenatal diagnosis with CVS or amniocentesis. A patient with a positive test result should be referred for genetic counseling and offered invasive prenatal diagnosis for confirmation of test results. A negative result does not ensure an unaffected pregnancy nor does it exclude the possibility of other chromosomal abnormalities or birth defects which are not a part of these tests. An uninformative result may be reported, the causes of which may include, but are not limited to, insufficient sequencing coverage, noise or artifacts in the region, amplification or sequencing bias, or insufficient fetal fraction. These tests are not intended to identify pregnancies at risk for neural tube defects or ventral wall defects. Testing for whole chromosome abnormalities (including sex chromosomes) and for subchromosomal abnormalities could lead to the potential discovery of both fetal and maternal genomic abnormalities that could have major, minor, or no, clinical significance. Evaluating the significance of a positive or a non-reportable result may involve both invasive testing and additional studies on the mother. Such investigations may lead to a diagnosis of maternal chromosome or subchromosomal abnormalities, which on occasion may be associated with benign or malignant maternal neoplasms. These tests may not accurately identify fetal triploidy, balanced rearrangements, or the precise location of subchromosomal duplications or deletions; there may be detected by prenatal diagnosis with CVS or amniocentesis. The ability to report results may be impacted by maternal BMI, maternal weight, maternal systemic lupus erythematosus (SLE) and/or by certain pharmaceutical agents such as low molecular weight heparin (for example: Lovenox®, Xaparin®, Clexane®, and Fragmin®). The results of this testing, including the benefits and limitations, should be discussed with a qualified healthcare provider. Pregnancy managment decisions, including termination of pregnancy, should not be based on the results of these tests alone. The healthcare provider is responsible for the use of this information in the management of their patient.

This test was developed, and its performance characteristics determined, by LabCorp. It has not been cleared or approved by the US Food and Drug Administration (FDA).

Methodology

Cell-free DNA is isolated from the sample and analyzed using massively parallel sequencing technology.

Specimen Requirements

Information on collection, storage, and volume

Specimen

Whole blood

Volume

(1) 10 mL

Minimum Volume

8 mL

Container

Black-and-tan-top (Streck) tube (whole blood). Sequenom collection kits are available (PeopleSoft No. 116373 379551G-CS-LCA.SEQUENOM-LCA.SEQUENOM-LCA ONLY KIT EA=1/KIT and PeopleSoft No. 116374 549403G-CS-LCA.SEQUENOM-LCA TEST REG STICKERS ST=3/SET).

Storage Instructions

Room temperature. Do not refrigerate or freeze. Keep out of direct sunlight. Samples must be shipped to LabCorp in a Sequenom collection kit.

Causes for Rejection

Gestational age less than nine weeks; expired or incorrect blood tubes (including nonglass tubes); quantity not sufficient for analysis; received more than seven days from collections; excessive hemolysis; frozen specimens

Collection

Only the Sequenom collection kit (PeopleSoft No. 116373) can be used for collection.