Collect whole blood in a purple top (EDTA) tube (preferred). Extracted DNA and saliva are also acceptable.
Specimen Preparation
Please provide detailed clinical history and features. For more information contact the lab at 6-1447 or by sending an email to DGDGeneticCounselor@chop.edu.
Unacceptable Conditions
Heparinized specimens, severely hemolyzed specimens, frozen, clotted or possibly commingled specimens, blood in non-sterile or leaky containers, mislabeled or inappropriately labeled specimens.
Storage/Transport Temperature
For CHOP Phlebotomy: Samples can be collected throughout the week. Samples collected on weekends or holidays are held in Central Labs and sent to the Genomic Diagnostic Lab the following business day.
For External Clients: Refrigerate sample until shipment. Send the sample at room temperature with overnight delivery for receipt Monday through Friday, optimally within 24 hours of collection.
Please contact the lab (267-426-1447) with questions regarding non-blood specimens.
Volume Required
2-3 mL of blood or 3 ug of DNA with a concentration of at least 50 ng/ul
Minimum Required
1 mL of whole blood
Phlebotomy Draw
Yes
Clinical Features
Hemophagocytic lymphohistiocytosis (HLH) is a heterogeneous inflammatory disorder characterized by immune activation and the release of cytokines. HLH presents with fever, splenomegaly, cytopenias (affecting at least two of three lineages), hypertriglyceridemia, hemophagocytosis (in bone marrow, spleen, lymph nodes or liver), low or absent NK-cell activity, increased ferritin, and elevated soluble CD25. Additional features may include neurologic abnormalities (increased cranial pressure, irritability, neck stiffness, hypotonia, hypertonia, convulsions, etc.), liver dysfunction, rash, and lymphadenopathy [Jordan 2019, PMID: 31339233; George 2014, PMID: 24966707; Mehta 2020, PMID: 32373790; Akenroye 2017, PMID: 28120605]. The HLH Panel focuses on genes that cause primary HLH (including PRF1, UNC13D, STX11, and STXBP2), as well as genes associated with several immunodeficiency syndromes such as Griscelli syndrome, Hermansky-Pudlak syndrome, Chediak-Higashi syndrome, lysinuric protein intolerance, various forms of lymphoproliferative syndrome, and chronic granulomatous disease.
Performing Lab
Division of Genomic Diagnostics
Performed
Monday to Friday, 9:00 am to 4:00 pm
Reported
14 days
Detection Rate
The clinical sensitivity for the Hemophagocytic Lymphohistiocytosis Seq Panel is not yet established but is expected to be greater than 70% of patients with primary hemophagocytic lymphohistiocytosis having findings in PRF1, UNC13D, STX11, and STXBP2 [PMID: 20301617].. While most disease causing variants in these genes are sequence variants, copy number alterations have also been described [PMID: 15703195, 29596912]. In addition, this test assays the pathogenic recurrent 253kb inversion variant in UNC13D, which is primarily observed in individuals of Scandinavian ancestry [PMID:21931115].
Utility
The clinical utility of the assay is to support a clinical diagnosis of hemophagocytic lymphohistiocytosis and facilitate genetic counseling, including risk assessment for other family members.
Genomic DNA is extracted from patient tissue following standard DNA extraction protocols. Whole genome sequencing is performed on the Illumina NovaSeq 6000 platform using the Illumina DNA PCR-Free Library Prep with 150bp paired-end reads. Mapping and analysis are based on the GRCh38 reference sequence. Sequencing data is processed using the Dragen pipeline (Illumina) to call both sequence and copy number variants. Long-range polymerase chain reaction (LR-PCR) is performed for the IKBKG gene followed by next generation sequencing.
Molecular Testing Notes
AP3B1, AP3D1, BLOC1S6, CARMIL2, CD27, CD70, CTPS1, CYBA, CYBB, FAAP24, HPS6, IFNGR1, IFNGR2, IL12RB1, IRF8, ITK, LYST, MAGT1, MCM4, NCF2, IKBKG*, NFKB1, PIK3CD*, PIK3R1, PRF1, PRKCD, RAB27A, RASGRP1, SH2D1A, SLC7A7, STAT1, STX11, STXBP2, STXBP3, UNC13D#, XIAP.
* Sequence analysis only is performed for these genes.
# Analysis of the pathogenic recurrent 253kb inversion in the UNC13D gene is included.
CPT Codes
81479, 81404, 81405
Collection
Collect
Collect whole blood in a purple top (EDTA) tube (preferred). Extracted DNA and saliva are also acceptable.
Specimen Preparation
Please provide detailed clinical history and features. For more information contact the lab at 6-1447 or by sending an email to DGDGeneticCounselor@chop.edu.
Unacceptable Conditions
Heparinized specimens, severely hemolyzed specimens, frozen, clotted or possibly commingled specimens, blood in non-sterile or leaky containers, mislabeled or inappropriately labeled specimens.
Storage/Transport Temperature
For CHOP Phlebotomy: Samples can be collected throughout the week. Samples collected on weekends or holidays are held in Central Labs and sent to the Genomic Diagnostic Lab the following business day.
For External Clients: Refrigerate sample until shipment. Send the sample at room temperature with overnight delivery for receipt Monday through Friday, optimally within 24 hours of collection.
Please contact the lab (267-426-1447) with questions regarding non-blood specimens.
Volume Required
2-3 mL of blood or 3 ug of DNA with a concentration of at least 50 ng/ul
Minimum Required
1 mL of whole blood
Phlebotomy Draw
Yes
Ordering
Clinical Features
Hemophagocytic lymphohistiocytosis (HLH) is a heterogeneous inflammatory disorder characterized by immune activation and the release of cytokines. HLH presents with fever, splenomegaly, cytopenias (affecting at least two of three lineages), hypertriglyceridemia, hemophagocytosis (in bone marrow, spleen, lymph nodes or liver), low or absent NK-cell activity, increased ferritin, and elevated soluble CD25. Additional features may include neurologic abnormalities (increased cranial pressure, irritability, neck stiffness, hypotonia, hypertonia, convulsions, etc.), liver dysfunction, rash, and lymphadenopathy [Jordan 2019, PMID: 31339233; George 2014, PMID: 24966707; Mehta 2020, PMID: 32373790; Akenroye 2017, PMID: 28120605]. The HLH Panel focuses on genes that cause primary HLH (including PRF1, UNC13D, STX11, and STXBP2), as well as genes associated with several immunodeficiency syndromes such as Griscelli syndrome, Hermansky-Pudlak syndrome, Chediak-Higashi syndrome, lysinuric protein intolerance, various forms of lymphoproliferative syndrome, and chronic granulomatous disease.
Performing Lab
Division of Genomic Diagnostics
Performed
Monday to Friday, 9:00 am to 4:00 pm
Reported
14 days
Detection Rate
The clinical sensitivity for the Hemophagocytic Lymphohistiocytosis Seq Panel is not yet established but is expected to be greater than 70% of patients with primary hemophagocytic lymphohistiocytosis having findings in PRF1, UNC13D, STX11, and STXBP2 [PMID: 20301617].. While most disease causing variants in these genes are sequence variants, copy number alterations have also been described [PMID: 15703195, 29596912]. In addition, this test assays the pathogenic recurrent 253kb inversion variant in UNC13D, which is primarily observed in individuals of Scandinavian ancestry [PMID:21931115].
Utility
The clinical utility of the assay is to support a clinical diagnosis of hemophagocytic lymphohistiocytosis and facilitate genetic counseling, including risk assessment for other family members.
Genomic DNA is extracted from patient tissue following standard DNA extraction protocols. Whole genome sequencing is performed on the Illumina NovaSeq 6000 platform using the Illumina DNA PCR-Free Library Prep with 150bp paired-end reads. Mapping and analysis are based on the GRCh38 reference sequence. Sequencing data is processed using the Dragen pipeline (Illumina) to call both sequence and copy number variants. Long-range polymerase chain reaction (LR-PCR) is performed for the IKBKG gene followed by next generation sequencing.
Molecular Testing Notes
AP3B1, AP3D1, BLOC1S6, CARMIL2, CD27, CD70, CTPS1, CYBA, CYBB, FAAP24, HPS6, IFNGR1, IFNGR2, IL12RB1, IRF8, ITK, LYST, MAGT1, MCM4, NCF2, IKBKG*, NFKB1, PIK3CD*, PIK3R1, PRF1, PRKCD, RAB27A, RASGRP1, SH2D1A, SLC7A7, STAT1, STX11, STXBP2, STXBP3, UNC13D#, XIAP.
* Sequence analysis only is performed for these genes.
# Analysis of the pathogenic recurrent 253kb inversion in the UNC13D gene is included.
