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Test Code FHLH UM Familial Hemophagocytic Lymphohistiocytosis (FHLH) Panel

Clinical System Name

Familial Hemophagocytic Lymphohistiocytosis (FHLH) Panel


The panel uses next-generation sequencing to detect most mutations in the genes listed below. The assay completely sequences all exons of these genes, detects large deletions and duplications, and has the potential to detect mosaicism.


The 11 genes in this panel include: 



Sample Requirements

Specimen: Whole Blood

Container(s): Lavender Top/EDTA, Yellow Top/ACD A or B, Dark Green Top/Sodium Heparin (no serum separator)

Preferred Vol: 10 mL

Minimum Vol:   5 mL


Specimen: DNA

Container(s): Sterile plastic tube

Preferred Vol: 6 micrograms, concentration: at least 25 nanograms/microliter

Minimum Vol:  3 micrograms


Specimen: Fresh frozen tissue

Container(s): Sterile cup or tube

Preferred Vol: 200-300mg

Minimum Vol: 50mg


Specimen: Cultured cells

Acceptable:  Fibroblasts

Container(s): T-25 flasks

Preferred Vol: 2 flasks


Buccal, saliva, and prenatal specimens are not accepted for this test at this time.

Processing Instructions

Reject due to:

Spin: No

Aliquot: No

Temp: 2 - 4 C

Storage location: Affix large Cerner labels to tubes and place in room temp send-outs rack. Store extra labels and copy of requisition in the clear plastic box attached to CPA refrigerator. Alert Send-outs team.


Off-site collection: Send whole blood refrigerated.


Specimen Type Temperature Time
Whole blood Room temp  
Whole blood Refrigerated 7 d
Whole blood Frozen N
Extracted DNA from blood or cultured fibroblasts Room temp 3-4 d
Extracted DNA from blood or cultured fibroblasts Refrigerated 1 y
Extracted DNA from blood or cultured fibroblasts Frozen Indefinitely
Fresh frozen tissue Frozen  
Cultured cells Room temp 3 days



No 8 weeks


Performing Laboratory

University of Washington

Department of Laboratory Medicine

UW Genetics Lab
1959 NE Pacific St, NW220
Seattle, WA 98195

Phone Number: (206) 520-4600


Department: Send Outs

Phone Number: (206) 987-2563



Reference Range

Interpretive report provided.


Method: Next-generation sequencing.

This assay sequences all exons of multiple genes associated with inherited immune deficiency syndromes. The average coverage ranges from 320 to >1,000 sequencing reads per bp. Genomic regions are captured using biotinylated RNA oliognucleotides (SureSelect), prepared in paired-end libraries with ~200 bp insert size, and sequenced on an Illumina HiSeq2500 instrument with 100 bp read lengths, in a modification of a procedure described by Pritchard et al. 2012 (1). Large deletions and duplications are detected using methods described by Nord et al. 2011 (2).

Special Instructions




Clinical Utility

This panel is useful for the evaluation of patients with suspected FHLH including:

  • Proliferation and infiltration of hyperactivated macrophages and T-lymphocytes
  • Evidence of hemophagocytosis in biopsy specimens
  • Recurrent, prolonged fevers
  • Cytopenias
  • Elevated liver enzymes
  • Hepatosplenomegaly
  • Low or absent natural killer (NK) cell activity

This panel is estimated to detect pathogenic variant(s) in >30-40% of individuals who meet clinical criteria for FHLH (Zur Stadt U et al., Hum Mutation 27:62–8 (2006); Jordan MB et al., Blood 118: 4041–52 (2011)).

Indications for testing include:
- Molecular genetic confirmation when one or more of the above conditions are suspected.

Send Out Instructions


Reference Test Name:

Immunoplex HLH Subpanel

Reference Test Number: IMD- HLH Subpanel
Instructions: Ship at room temperature, avoid freezing sample. Send out M - F with the UW courier.