Sign in →

Test Code CHI Panel Congenital Hyperinsulinism Sequencing Panel

Important Note

The Congenital Hyperinsulinism Sequencing Panel will no longer include UCP2 gene sequencing as of 5/30/18.  This decision is based on recent knowledge that supports evidence that UCP2 variants are not a direct cause of congenital hyperinsulinism (CHI) but instead are, at most, risk factors for CHI. See Clinical Utility section for more information.

 

The CHI Sequencing Panel will continue to include sequencing of the following genes: ABCC8, GCK, GLUD1, HADH, HNF1A, HNF4A, INSR, KCNJ11, and SLC16A1.

 

Providers and hospital staff may contact our Laboratory Genetic Counselors (206-987-5400 or LabGC@seattlechildrens.org) with questions.

Clinical System Name

Congenital Hyperinsulinism Sequencing Panel

Synonyms

CHI

FHI

Description

The Congenital Hyperinsulinism Sequencing panel includes DNA sequencing of ten genes associated with this condition:  ABCC8, GCK, GLUD1, HADH, HNF1A, HNF4A, INSR, KCNJ11, SLC16A1

 

Testing is appropriate for:

  • Infants with hyperinsulinism 

Sample Requirements

Specimen: Whole blood

Container(s): Lavender/EDTA

Preferred Vol: 3 mL

Minimum Vol: 1 mL

 

Note: Heparin samples (Green tops) are unacceptable.

 

Specimen: Extracted DNA

Minimum: 10µg

Note: DNA concentration minimum 100 µg/mL; 260/280 ratio 1.70-2.00

Processing Instructions

Reject due to: Heparin

Spin: No

Aliquot: No

Temp: Refrigerate

Storage location: Molecular Genetics box in CPA refrigerator #2

 

Off-site collection: Refrigerate blood samples until ready to ship.  Transport all sample types at room temperature via overnight shipping.

Stability

Specimen Type Temperature Time
Whole blood, extracted DNA Room temp 3-5 days
Whole blood, extracted DNA Refrigerated 7 days
Extracted DNA Frozen ok

 

Note: Whole blood samples > 7days may be submitted to be assessed by our lab for acceptability for testing.

Availability

STAT Performed TAT
Contact lab Monday - Friday 4-6 weeks

 

Performing Laboratory

Seattle Children's Laboratory

Department

Department:  Molecular Genetics Laboratory

Phone: 206-987-3872

 

Lab Client Services: 206-987-2617

 

Lab Genetic Counselor: LabGC@seattlechildrens.org

Reference Range

Interpretive report will be provided

Methodology

Method: Next Generation Sequencing technology using an Illumina NextSeq instrument. Target region includes all coding exons and exon/intron boundaries of the genes tested. Target enrichment performed using Agilent SureSelect Focused Exome.   

 

Limitations: This method can detect single nucleotide variants, small deletions,and small insertions. Large deletions and insertions, Copy Number Variants, large duplications, and variants in deep intronic non-coding regions will not be detected.

CPT Codes

Call or email Lab Client Services, (206-987-2617 or labclientservices@seattlechildrens.org) for price and CPT information.

Special Instructions

Links to: Familial Hyperinsulinism GeneReview;  DiabetesGenes.org

Requisition

Molecular Genetics

Clinical Utility

The Congenital Hyperinsulinism Sequencing panel includes DNA sequencing of nine genes associated with this condition:  ABCC8, GCK, GLUD1, HADH, HNF1A, HNF4A, INSR, KCNJ11, SLC16A1

Testing is appropriate for:

  • Infants with hyperinsulinism

 

ABCC8: Approximately 45% of CHI is attributed to mutations of ABCC8, the gene encoding the protein SUR-1, the second of the two components of the beta-cell plasma membrane ATP-dependent potassium channel.

 

KCNJ11:   Approximately 5% of CHI is attributed to mutations of KCNJ11, the gene encoding the protein Kir6.2 which is one of the two components of the beta-cell plasma membrane ATP-dependent potassium channel.

 

HNF4A:    Approximately 5% of CHI is attributed to mutations of  HNF4A, the gene encoding the hepatocyte nuclear factor 4-alpha.

 

As of 5/30/18, the Congenital Hyperinsulinism Sequencing Panel will no longer include UCP2 gene sequencing  This decision is based on recent knowledge that supports evidence that UCP2 variants are not a direct cause of congenital hyperinsulinism but instead are, at most, risk factors for CHI  [Laver TW, Weedon MN, Caswell R, Hussain K, Ellard S, Flanagan SE.  Analysis of large-scale sequencing cohorts does not support the role of variants in UCP2 as a cause of hyperinsulinaemic hypoglycaemia. Hum Mutat. 2017 Oct; 38(10):1442-1444. PMID: 28681398].