Test Id : DOCK8
Dedicator of Cytokinesis 8 (DOCK8) Deficiency, Blood
Useful For
Suggests clinical disorders or settings where the test may be helpful
Aiding in the diagnosis of dedicator of cytokinesis 8 (DOCK8) deficiency
This test is not useful for assessing DOCK8 carrier status.
Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request
The human DOCK8 gene is on chromosome 9.
Autosomal recessive germline pathogenic variants observed in dedicator of cytokinesis 8 (DOCK8) deficiency fall into the following main categories:
-Large homozygous deletions
-Compound heterozygous large deletion plus disease-causing missense variant (point alteration) or a small deletion/insertion (delin)
-Compound heterozygous disease-causing missense variants plus small deletions/insertions
A study of 34 patients with DOCK8 deficiency has shown variable degrees of somatic reversion in half of the cohort, mainly in memory T cells and NK cells. The extent of somatic reversion is inversely correlated with cumulative disease burden. This type of repair cannot happen in cases with large homozygous deletions.
Highlights
The test detects the expression of dedicator of cytokinesis 8 (DOCK8) in T cells, B cells, natural killer cells, and monocytes in the peripheral blood.
It can be used as a screening step prior to genetic testing for DOCK8; to confirm the finding of an established disease-causing alteration in DOCK8 at the protein level; to examine a reported variant of undetermined significance; and to evaluate the potential presence of somatic reversion in a patient with DOCK8 deficiency.
It can help distinguish DOCK8 deficiency from conditions with overlapping clinical manifestations, including Job syndrome (AD-HIES), ZNF341 deficiency, and severe atopic dermatitis.
Method Name
A short description of the method used to perform the test
Flow Cytometry
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
DOCK8 Deficiency
DOCK8
Dedicator of Cytokinesis 8
Specimen Type
Describes the specimen type validated for testing
Whole Blood EDTA
Ordering Guidance
This flow cytometry test is complementary to genetic testing.
Shipping Instructions
Testing is performed Monday through Friday. Specimens not received by 4 p.m. (CST) on Friday may be canceled.
Collect and package specimen as close to shipping time as possible. It is recommended that specimens arrive within 24 hours of collection.
Samples arriving on the weekend and observed holidays may be canceled.
Necessary Information
Ordering healthcare professional name and phone number are required.
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Container/Tube: Lavender top (EDTA)
Specimen Volume: 3 mL
Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
1 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | OK |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole Blood EDTA | Ambient | 48 hours | PURPLE OR PINK TOP/EDTA |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Aiding in the diagnosis of dedicator of cytokinesis 8 (DOCK8) deficiency
This test is not useful for assessing DOCK8 carrier status.
Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request
The human DOCK8 gene is on chromosome 9.
Autosomal recessive germline pathogenic variants observed in dedicator of cytokinesis 8 (DOCK8) deficiency fall into the following main categories:
-Large homozygous deletions
-Compound heterozygous large deletion plus disease-causing missense variant (point alteration) or a small deletion/insertion (delin)
-Compound heterozygous disease-causing missense variants plus small deletions/insertions
A study of 34 patients with DOCK8 deficiency has shown variable degrees of somatic reversion in half of the cohort, mainly in memory T cells and NK cells. The extent of somatic reversion is inversely correlated with cumulative disease burden. This type of repair cannot happen in cases with large homozygous deletions.
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Dedicator of cytokinesis 8 (DOCK8) is an atypical guanine exchange factor that plays a role in regulating actin polymerization and cytoskeletal rearrangement. DOCK8 is important in both innate and adaptive immunity by contributing to cellular migration, cytotoxicity, antibody production, and immunological memory.
DOCK8 deficiency is a rare, combined immunodeficiency with an autosomal recessive inheritance that typically presents in childhood. Its clinical features include atopic disease, recurrent sinopulmonary infections, cutaneous viral infection, Staphylococcus aureus skin infections, and cancer.
DOCK8 deficiency is diagnosed based on clinical phenotype, immunologic findings, and molecular analysis.
Diseases in the differential diagnosis include Job syndrome (AD-HIES), ZNF341 deficiency, and severe atopic dermatitis.
Assessment of DOCK8 expression on immune cells is an important component and facilitates the diagnosis of this condition and the timely treatment of the patient.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
The appropriate reference values will be provided on the report.
Interpretation
Provides information to assist in interpretation of the test results
The results will be reported as the percentage of dedicator of cytokinesis 8 (DOCK8) expression on T cells, B cells, natural killer (NK) cells, and monocytes.
The absence of DOCK8 expression on all cell types will be consistent with DOCK8 deficiency. In this case, genetic analysis of DOCK8 to confirm the diagnosis and to identify the underlying alteration will be recommended.
The expression of DOCK8 on a subset of T cells and/or NK cells could suggest somatic reversion in a patient with DOCK8 deficiency, which can modulate disease phenotype over time.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test cannot be relied upon for identifying carrier status for dedicator of cytokinesis 8 deficiency.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Engelhardt KR, McGhee S, Winkler S, et al. Large deletions and point mutations involving the dedicator of cytokinesis 8 (DOCK8) in the autosomal-recessive form of hyper-IgE syndrome. J Allergy Clin Immunol. 2009; 124(6):1289-302 e4. doi:10.1016/j.jaci.2009.10.038
2. Jing H, Zhang Q, Zhang Y, et al. Somatic reversion in dedicator of cytokinesis 8 immunodeficiency modulates disease phenotype. J Allergy Clin Immunol. 2014;133(6):1667-1675. doi:10.1016/j.jaci.2014.03.025
3. Pai SY, de Boer H, Massaad MJ, et al. Flow cytometry diagnosis of dedicator of cytokinesis 8 (DOCK8) deficiency. J Allergy Clin Immunol. 2014;134(1):221-223. doi:10.1016/j.jaci.2014.02.023
4. Engelhardt KR, Gertz ME, Keles S, et al. The extended clinical phenotype of 64 patients with dedicator of cytokinesis 8 deficiency. J Allergy Clin Immunol. 2015;136(2):402-412. doi:10.1016/j.jaci.2014.12.1945
5. Su HC, Jing H, Angelus P, Freeman AF. Insights into immunity from clinical and basic science studies of DOCK8 immunodeficiency syndrome. Immunol Rev. 2019;287(1):9-19. doi:10.1111/imr.12723
6. Aydin SE, Freeman AF, Al-Herz W, et al. Hematopoietic stem cell transplantation as treatment for patients with DOCK8 deficiency. J Allergy Clin Immunol Pract. 2019;7(3):848-855. doi:10.1016/j.jaip.2018.10.035
Method Description
Describes how the test is performed and provides a method-specific reference
The dedicator of cytokinesis 8 (DOCK8) protein expression assay is performed on whole blood. Samples are fixed, permeabilized, and stained with antibodies specific for CD45, CD14, CD19, CD3, and CD56 along with either the DOCK8 antibody (unconjugated) or isotype control (unconjugated). A secondary mouse anti-rabbit reporter antibody is added to allow the assessment of DOCK8 and isotype control expression. Samples are then analyzed on a flow cytometer. DOCK8 expression is evaluated on the following populations: T cells: (CD45+CD14[neg]CD3+), B cells: (CD45+CD14[neg]CD3[neg]CD19+), natural killer-cells (CD45+CD14[neg]CD3[neg]CD56+), Monocytes (CD45+CD14+).(Unpublished Mayo method)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday through Friday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
- Authorized users can sign in to Test Prices for detailed fee information.
- Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
- Prospective clients should contact their account representative. For assistance, contact Customer Service.
Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
This test was developed using an analyte specific reagent. Its performance characteristics were 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.
CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
86356 x 4
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| DOCK8 | DOCK8 Deficiency, B | 96415-5 |
| 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.
|
|---|---|---|
| 608496 | %CD3+DOCK8+ | 96416-3 |
| 608497 | %CD19+DOCK8+ | 96417-1 |
| 608498 | %CD56+DOCK8+ | 96418-9 |
| 608499 | %CD14+DOCK8+ | 96419-7 |
| 608513 | DOCK8 Interpretation | 69052-9 |