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Test ID DOCK8 Dedicator of Cytokinesis 8 (DOCK8) Deficiency, Blood


Ordering Guidance


This flow cytometry test is complementary to genetic testing.



Shipping Instructions


Specimens are required to be received in the laboratory weekdays and by 4 p.m. on Friday. 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 physician name and phone number are required.



Specimen Required


Container/Tube: Lavender top (EDTA)

Specimen Volume: 3 mL

Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.


Useful For

Aiding in the diagnosis of dedicator of cytokinesis 8 (DOCK8) deficiency

 

This test is not useful for assessing DOCK8 carrier status.

Genetics Test Information

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

Flow Cytometry

Reporting Name

DOCK8 Deficiency, B

Specimen Type

Whole Blood EDTA

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole Blood EDTA Ambient 48 hours PURPLE OR PINK TOP/EDTA

Reference Values

The appropriate reference values will be provided on the report.

Day(s) Performed

Monday through Friday

Report Available

2 to 4 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

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

86356 x 4

LOINC Code Information

Test ID Test Order Name Order LOINC Value
DOCK8 DOCK8 Deficiency, B 96415-5

 

Result ID Test Result Name Result LOINC Value
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

NY State Approved

Yes