Standard Genome Sequencing (GS) and Rapid Genome Sequencing (rGS)
Overview
The NYGC’s standard and rapid clinical genome sequencing tests are offered as a trio-test in which the affected patient of interest (proband) together with two first-degree relatives (usually the biological parents) are sequenced together. Sequencing data is analyzed in the context of family relationships to increase the likelihood of identifying genetic variants that may be contributing to the symptoms observed in the child. The NYGC’s Clinical Laboratory also accepts samples from just the affected individual, as well as from other affected or unaffected relatives, as appropriate to provide additional context and help guide interpretation on a case-by-case basis.
Knowledge of disease-causing mutations is changing at a rapid pace. To help clinicians better serve their patients, the NYGC’s proprietary genome sequencing pipeline incorporates up-to-date variant databases and disease-specific databases to keep pace with the ever-changing growth in knowledge. Additionally, GS and rGS may also identify variants in genes previously not linked to a disease (novel genes). Since genome sequencing interrogates all protein-coding regions, it replaces the potential need for multiple costly single-gene tests, avoids clinician guesswork or bias in gene testing decisions, improves the odds of identifying a high-risk variant and thereby improves the diagnostic success rate and guidance of appropriate clinical management.
Deliverables
The NYGC’s Clinical Laboratory returns GS results within 4-6 weeks on a standard basis and provides rapid turnaround for rGS. Due to the complexity of genetic testing and the potential implications of the results, the results are sent to the physician and/or genetic counselor who then discuss the results with the patient. The results of the tests can become part of the patient’s medical record.
A report will be provided indicating the variants that could explain the clinical phenotype. In addition, patients can consent for reporting secondary findings in medically actionable genes as per the American College of Medical Genetics and Genomics (ACMG) guidelines.
Ordering Instructions
A physician can order the test using the NYGC’s test requisition form and must obtain informed consent from each family member (in pediatric cases, the child’s parents) being tested. This test requires at least 2ml of blood drawn in an EDTA tube or saliva specimen collected in an Oragene Dx collection kit or DNA extracted in a CLIA-certified laboratory from each family member being tested (all samples submitted together whenever possible). Prenatal testing requires direct or cultured amniotic fluid or chorionic villi samples. For direct specimens, at least 5ml of amniotic fluid or 10mg of cleaned chorionic villi should be collected in a 15ml tube. For cultured specimens, 2 T25 flasks (70-80% confluent) are required. Fetal parts are also acceptable for prenatal testing and Fetal parts such as liver or muscle (2x2x2 cm) should be stored in transport medium or saline and sent to the laboratory as soon as possible after collection. Samples should be shipped to the NYGC overnight via FedEx. A courier service may also be feasible.