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Test Code NGENZ Red Blood Cell Enzyme Panel, Next-Generation Sequencing, Varies

Secondary ID

64937

Useful For

Providing a comprehensive genetic evaluation for patients with a personal or family history suggestive of an underlying RBC enzymopathy

 

Identifying mutations within genes associated with phenotypic severity, allowing for predictive testing and further genetic counseling

Method Name

Next-Generation Sequencing (NGS)

Reporting Name

RBC Enzyme Sequencing, V

Specimen Type

Varies


Shipping Instructions


Peripheral blood specimens must arrive within 30 days of collection.



Necessary Information


1. Metabolic Hematology Next-Generation Sequencing (NGS) Patient Information is required, see Special Instructions. Testing may proceed without the patient information, however, the information aids in providing a more thorough interpretation. Ordering providers are strongly encouraged to fill out the form and send with the specimen.

2. If form not provided, include the following information with the test request: clinical diagnosis, pertinent clinical history (ie, CBC results and relevant clinical notes) and differentials based on clinical or morphologic presentation.



Specimen Required


Submit only 1 of the following specimens:

 

Specimen Type: Peripheral blood (preferred)

Container/Tube:

Preferred: Lavender top (EDTA) or Yellow top or (ACD)

Acceptable: Green top (heparin)

Specimen Volume: 3 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube.

3. Label specimen as blood

Specimen Stability: Refrigerated ≤30 days

 

Specimen Type: Extracted DNA

Container/Tube: 1.5- to 2-mL tube

Specimen Volume: Entire specimen

Collection Instructions:

1. Indicate volume and concentration of the DNA.

2. Label specimen as extracted DNA and source of specimen.

Specimen Stability: Frozen/Refrigerated/Ambient ≤30 days


Specimen Minimum Volume

Blood, Bone Marrow: 1 mL
Extracted DNA: 100 mcL at 20 ng/mcL concentration

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Varies

Reject Due To

Gross hemolysis Reject
Gross lipemia OK
Other Bone marrow biopsies Slides Paraffin shavings Frozen tissues Paraffin-embedded tissues Paraffin-embedded bone marrow aspirates

Clinical Information

Next-generation sequencing (NGS) is a methodology that can interrogate large regions of genomic DNA in a single assay. The presence and pattern of gene mutations can provide critical diagnostic, prognostic, and therapeutic information for managing physicians.

 

This panel aids in the diagnosis and genetic counseling of individuals with inherited RBC enzymopathies, possible carrier states, or compound mutations with severity modulating interactions. This panel always should be interpreted in the context of protein functional findings by enzymatic assay and complete blood count and peripheral blood findings. This complete interpretation can be provided by also ordering the EEEVP / RBC Enzyme Evaluation. Please fill out the information sheet and indicate that NGS testing was ordered. Providing CBC data and clinical notes will also allow more precise interpretation of results.

 

Mature erythrocytes are dependent upon glycolysis for energy production and the hexose monophosphate shunt for oxidation-reduction stability. Hereditary deficiencies in RBC enzymes within these pathways cause nonspherocytic hemolytic anemia (NSHA) with variable clinical presentations, therapeutic considerations and inheritance patterns.(1-3) Most of these deficiencies cause chronic hemolysis with little to no pathognomonic morphologic changes in the peripheral blood smear making correlation with enzyme activity critical for diagnosis. Some are associated with acute episodic anemia triggered by medications, food, or viral illness. Variable additional symptoms may be present for some deficiency types, including myopathy, neuropathy, and developmental delay. Because a subset of clinically significant RBC enzyme disorders can have indeterminate to normal enzyme activity (masking in the presence of increased reticulocytes), the protein  (enzymatic activity) studies are more sensitive when performed as a panel of RBC enzymes, which allows comparison of multiple enzyme activities. This genetic panel can aid in the interpretation of equivocal protein findings and genetically confirm an enzyme deficiency. Additionally, there are genes interrogated on this panel for which an enzyme test is not clinically available for correlation.

Reference Values

An interpretive report will be provided.

Interpretation

Evaluation and categorization of variants is performed using the most recent published American College of Medical Genetics recommendations as a guideline.(4,5) Variants are classified based on known, predicted, or possible pathogenicity and reported with interpretive comments detailing their potential or known significance.

 

Multiple in silico evaluation tools may be used to assist in the interpretation of these results. The accuracy of predictions made by in silico evaluation tools is highly dependent upon the data available for a given gene, and predictions made by these tools may change over time. Results from in silico evaluation tools should be interpreted with caution and professional clinical judgment.

Clinical Reference

1. Nathan and Oski's Hematology of Infancy and Childhood. Edited by SH Orkin, DG Nathan, D Ginsburg, et al. Seventh edition. Philadelphia, Saunders Elsevier, 2009, pp 360-364

2. Iolascon A, Andolfo I, Barcellini W, et al: Recommendations for splenectomy in hereditary hemolytic anemias. Haematologica 2017 May 26. PMID: 28550188. doi: 10.3324/haematol.2016.161166.

3. Koralkova P, van Solinge WW, van Wijk R: Rare hereditary red blood cell enzymopathies associated with hemolytic anemia - pathophysiology, clinical aspects, and laboratory diagnosis. Int J Lab Hematol 2014 Jun;36(3):388-397

4. Richards S, Aziz N, Bale S, et al: Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Genet Med 2015;17:405-424

Day(s) and Time(s) Performed

Monday

Analytic Time

8 weeks

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

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 U.S. Food and Drug Administration.

CPT Code Information

81443

LOINC Code Information

Test ID Test Order Name Order LOINC Value
NGENZ RBC Enzyme Sequencing, V In Process

 

Result ID Test Result Name Result LOINC Value
NGENS Specimen Type 31208-2
NGEND Indication for Test 42349-1
40560 Alterations Detected 82939-0
40561 Interpretation 59465-5
40562 Additional Notes 48767-8
40563 Method Summary 49549-9
40564 Disclaimer 62364-5
40566 Panel Gene List 36908-2
40567 Reviewed By 18771-6

Forms

1. Metabolic Hematology Next-Generation Sequencing (NGS) Patient Information is required, see Special Instructions.

2. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826) 

Testing Algorithm

See NGHHA and Subpanel Comparison Gene List in Special Instructions.