Inheritest Gene-specific Sequencing, NGS
Varies by gene; please call 800-848-4436
Prenatal testing: Integrated Genetics clients should call 800-848-4436 to speak to a laboratory genetic coordinator before collecting any specimens. In some circumstances, specimens from other family members may be required.
All prenatal specimens (including cord blood) must be accompanied by a maternal blood or mouthwash specimen for analysis of possible maternal cell contamination.
Discard first 2 mL; then 20 mL amniotic fluid in 15 mL orange-top polypropylene tubes, 20 mg chorionic villi in laboratory-provided screw-top tubes with sterile transport medium or two T-25 flasks of confluent cells.
Additional sample must be obtained for back-up culture at one of our cytogenetics laboratories or another facility.
If additional testing is desired, more amniotic fluid is needed. For example, chromosome analysis requires an additional 15-25 mL (see Cytogenetics – Amniotic Fluid Chromosome Analysis test page) and AFAFP requires an additional 2 mL (see Amniotic Fluid Alpha-Fetoprotein - AFAFP test page).
Postnatal: peripheral blood
Prenatal: amniotic fluid, chorionic villi, cultured amniocytes, cultured chorionic villi
Postnatal: 10 cc peripheral blood
Prenatal: 20 mL amniotic fluid in orange-top polypropylene tube, 20 mg chorionic villi in laboratory provided screw-top tubes with sterile transport medium or two T-25 flask of confluent cells.
Lavender-top (EDTA) tube, yellow-top (ACD-A) tube
Maintain specimen at room temperature.
Causes for Rejection
Frozen specimen; hemolysis; quantity not sufficient for analysis; improper container; unlabeled or mislabeled specimen
False-positive and false-negative results may occur for reasons that include genetic variants, blood transfusions, bone marrow transplantation, erroneous representation of family relationships, or contamination of a fetal sample with maternal cells.
Mutation analysis is performed using the Agilent® SureSelect® XT enrichment method and the Illumina® next-generation sequencing platform. Regions of interest include all exons and splice junctions for each gene analyzed. Sequencing reads are aligned with the hg19 build of the human genome reference sequence. Greater than 98% of target bases are covered at greater than or equal to 20x coverage. Analytical sensitivity for this assay is estimated to be >99%. The clinical significance of variants is assessed according to a proprietary algorithm. Variants known to be benign are not reported. Reported variants are confirmed by Sanger sequencing and described using numbering and nomenclature recommended by the Human Genome Variation Society (HGVS). Detailed variant scoring information is avaiable upon request. This analysis does not detect germline mosaicism, and does not rule out the presence of large chromosomal aberrations including deletions, insertions, and rearrangements, or mutations in regions or genes not included in this test, and possible inter/intragenic interactions between sequence variants.