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Test ID KCNN4 KCNN4 Full Gene Sequencing, Varies

Necessary Information

The following information is required on either the Metabolic Hematology Next-Generation Sequencing (NGS) Patient Information (T816) or test request form:

1. Clinical diagnosis

2. Pertinent clinical history (submit complete blood cell count results and relevant clinical notes)

3. Differentials based on clinical or morphologic presentation

4. Date of collection

5. Specimen type, whole blood or extracted DNA

Specimen Required

Submit only 1 of the following specimens:



Specimen Type: Whole blood


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

Acceptable: Green top (heparin)

Specimen Volume: 3 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send whole blood specimen in original tube. Do not aliquot.

3. Label specimen as blood.

Specimen Stability Information: Ambient 14 days (preferred)/Refrigerated ≤30 days



Specimen Type: Extracted DNA from whole blood

Container/Tube: 1.5- to 2-mL tube with indication of volume and concentration of DNA

Specimen Volume: Entire specimen

Collection Instructions: Label specimen as extracted DNA from blood and provide indication of volume and concentration of the DNA

Specimen Stability Information: Frozen/Refrigerate/Ambient ≤30 days


1. Metabolic Hematology Next-Generation Sequencing (NGS) Patient Information (T816) is required.

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:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826)

3. If not ordering electronically, complete, print, and send a Benign Hematology Test Request (T755) with the specimen.

Useful For

Genetic confirmation of a dehydrated hereditary stomatocytosis-2/hereditary xerocytosis diagnosis with the identification of an alteration known or suspected to cause disease in the KCNN4 gene


Second-tier testing for patients in whom previous targeted gene variant analyses were negative for a specific red blood cell (RBC) membrane disorder


Establishing a diagnosis of a hereditary RBC membrane disorder, allowing for appropriate management and surveillance of disease features based on the gene involved, especially if splenectomy is a consideration

Method Name

Polymerase Chain Reaction (PCR) Amplification/Sanger Sequencing

Reporting Name

KCNN4 Full Gene Sequencing, V

Specimen Type


Specimen Minimum Volume

Blood: 1 mL
Extracted DNA: 50 mcL at 50 ng/mcL concentration

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Varies

Reference Values

An interpretive report will be provided.

Day(s) Performed

Monday through Friday

Report Available

56 to 70 days

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 US Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
KCNN4 KCNN4 Full Gene Sequencing, V 98954-1


Result ID Test Result Name Result LOINC Value
607810 Interpretation 82939-0
607811 Signing Pathologist 19139-5