Submitting a biological family member's specimen to be used as a comparator for affected patients (probands) undergoing whole genome sequencing
This test is for the biological family members whose specimens are being submitted as comparators for patients undergoing WGSDX / Whole Genome Sequencing for Hereditary Disorders, Varies.
Polymerase Chain Reaction-Free Next-Generation Sequencing followed by Sanger Sequencing, Quantitative Polymerase Chain Reaction (qPCR), or other methods, as needed
Brother
Child
Children
CMPRG
Comparator
Dad
Daughter
Duo
Family member
Father
Genome
Genome sequencing
Genomic
Maternal
Mom
Mother
NextGen Sequencing Test
NGS
Non-traditional trio
Paternal
Quad
Relative
Sibling
Singleton
Sister
Son
Trio
WGS
Whole
Whole genome
Whole-genome
Varies
This test is not appropriate for affected patients (probands) undergoing whole genome sequencing (WGS). This test is intended to be ordered for biological family member comparator specimens only. For WGS testing for the proband, order WGSDX / Whole Genome Sequencing for Hereditary Disorders, Varies. If this test is ordered on a proband, the test will be canceled and WGSDX will be performed as the appropriate test.
If this test is ordered on a family member comparator of a proband having WESDX / Whole Exome Sequencing for Hereditary Disorders, Varies; or WESMT / Whole Exome and Mitochondrial Genome Sequencing, Varies, this test will be canceled and CMPRE / Family Member Comparator Specimen for Exome Sequencing, Varies performed as the appropriate test.
Each specimen must be on a separate order.
1. Order WGSDX / Whole Genome Sequencing for Hereditary Disorders, Varies on the patient (proband).
2. Order this test on all family members' specimens being submitted as comparators.
a. When available, the patient's biological mother and biological father are the preferred family member comparators.
b. If one or both of the patient's biological parents are not available for testing, specimens from other first-degree relatives (siblings or children) can be used as comparators. Testing typically includes up to 2 family member comparators. Contact the laboratory at 800-533-1710 for approval to send specimens from other relatives or to send the patient and 3 first-degree relatives (quad).
c. The cost of analysis for family member comparator specimens is applied to the patient's (proband's) test. Family members will not be charged separately.
3. Collect patient (proband) and family member specimens. Label specimens with full name and birthdate. Do not label family members' specimens with the proband's name.
4. For each family, complete the following portions of the Whole Genome Sequencing: Ordering Checklist. A separate form is not needed for each family member.
a. Patient Information is required for all clients
b. Informed Consent is required for New York State clients
c. If the patient wishes to opt-out of receiving secondary findings or change the DNA storage selection, select the appropriate boxes in the Informed Consent section.
5. Attach clinic notes from specialists relevant to patient's clinical features, if available.
6. Attach pedigree, if available.
7. Send paperwork to the laboratory along with the specimens. If not sent with the specimens, fax a copy of the paperwork to 507-284-1759, Attn: WGS Genetic Counselors.
Specimen preferred to arrive within 96 hours of collection.
Whole Genome Sequencing: Ordering Checklist is required for all clients, and Informed Consent is required for New York clients. Fill out one form for the family and send with the specimens.
Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.
Specimen Type: Whole blood
Container/Tube:
Preferred: Lavender top (EDTA) or yellow top (ACD)
Acceptable: Any anticoagulant
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
1. Whole Genome Sequencing: Ordering Checklist is required.
2. New York Clients-Informed consent is required, included in the above form. Document on the request form or electronic order that a copy is on file.
1 mL
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Varies | Ambient (preferred) | ||
Frozen | |||
Refrigerated |
Submitting a biological family member's specimen to be used as a comparator for affected patients (probands) undergoing whole genome sequencing
This test is for the biological family members whose specimens are being submitted as comparators for patients undergoing WGSDX / Whole Genome Sequencing for Hereditary Disorders, Varies.
This test uses next-generation sequencing technology to assess the genome of patients with suspected underlying genetic disorders. This information is used to assist in the interpretation of the patient's (proband's) whole genome sequencing results (WGSDX / Whole Genome Sequencing for Hereditary Disorders, Varies). Ordering this test on biological family members of the affected proband can help determine the inheritance of genetic variants that are identified and if the variants segregate with a phenotype in the family. Submitting comparator samples from biological family members increases the chance of identifying a diagnosis in the proband. Whole genome sequencing is most informative when samples from both biological parents are used as comparators. Therefore, it is highly recommended that samples are also submitted from the patient's biological mother and biological father.
If more than 2 biological family member comparator specimens are submitted, the additional comparator specimens may not be fully sequenced but rather used for confirmatory presence or absence of identified variants of interest after initial variant calling and review.
An interpretive report will be provided
Interpretive information will only be provided on the proband's whole genome sequencing report (WGSDX / Whole Genome Sequencing for Hereditary Disorders, Varies). The presence of a variant in family member comparator samples is stated on the proband's report. Variants that are present in family member comparator samples but absent from the proband sample are not evaluated or reported.
Secondary Findings:
Patients are evaluated for medically actionable secondary findings and these findings are reported in accordance with the American College of Medical Genetics and Genomics recommendations.(1) The presence of a secondary finding in family member comparator samples is stated on the patient's (proband's) report unless family members opt-out of secondary findings. If the proband opts out, secondary findings will not be evaluated or reported in any family member comparators. Secondary findings that are present in family member comparators but absent from the patient (proband) are not evaluated or reported.
The absence of a reportable secondary finding does not guarantee that there are no disease-causing or likely disease-causing variants in these genes, as review is limited to known or highly suspected pathogenic findings, and not all regions of these genes are adequately evaluated by this technology.
This testing is intended to be used for biological family members whose specimens are being submitted as comparators for affected patients (probands) undergoing whole genome sequencing. Although test results will only be provided in the context of the proband, it is possible for family members serving as comparators to learn unexpected genetic information about themselves. For example, it is possible for individuals to learn that they carry certain genetic variants that are being reported in the proband, or that biological relationships are not as described.
It is not a guarantee that patient data will be stored indefinitely.
If the patient has had an allogeneic hematopoietic stem cell transplant or a recent blood transfusion, results may be inaccurate due to the presence of donor DNA. Call Mayo Clinic Laboratories at 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.
1. Miller DT, Lee K, Gordon AS, et al: Recommendations for reporting of secondary findings in clinical exome and genome sequencing, 2021 update: a policy statement of the American College of Medical Genetics and Genomics (ACMG). Genet Med. 2021 Aug;23(8):1391-1398
Polymerase chain-reaction-free next-generation sequencing is performed on DNA extracted from the patient (proband) and all applicable comparator samples to test for the presence of variants. The human genome reference GRCh38/hg38 build is used for sequence read alignment. Variants are called using an optimized bioinformatics package. The average genomic coverage is at or above a read depth of 32X. Sensitivity is estimated at above 99% for single nucleotide variants, above 94% for deletion-insertions (delins) less than 50 base pairs (bp). This assay also detects >99% copy number variants (deletions/duplications) at least 1000 bp in size. Confirmation of select reportable variants in the proband and submitted comparator samples may be performed by alternate methodologies based on internal laboratory criteria.
There may be regions of genes that cannot be effectively evaluated by sequencing as a result of technical limitations of the assay, including regions of homology, variable depth of coverage, and repetitive sequences.(Unpublished Mayo method)
Varies
This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
CMPRG | Family Member Comparator for Genome | 86206-0 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
614930 | Interpretation | 69047-9 |
614931 | Specimen | 31208-2 |
614932 | Source | 31208-2 |
614941 | Released By | 18771-6 |