KCNJ11-Related Congenital Hyperinsulinism via the KCNJ11 Gene

  • Summary and Pricing
  • Clinical Features and Genetics
  • Citations
  • Methods
  • Ordering/Specimens
Order Kits


Test Code Test Copy GenesIndividual Gene PriceCPT Code Copy CPT Codes
1218 KCNJ11$540.00 81403 Add to Order
Pricing Comment

Parental targeted testing for all probands with uncertain, likely pathogenic or pathogenic variants in the KCNJ11 gene are free of charge.

Targeted Testing

For ordering targeted known variants, please proceed to our Targeted Variants landing page.

Turnaround Time

The great majority of tests are completed within 18 days.

Clinical Sensitivity

In a cohort of 417 CHI patients studied at the Hyperinsulinism Center in The Children’s Hospital of Philadelphia (CHOP), approximately 11% (23/213) of mutations, regardless of inheritance pattern, were identified in the KCNJ11 gene via DNA sequencing (Snider, K. et al. J Clin Endocrinol Metab 98(2):E355-563, 2013). In another cohort of 300 CHI patients studied in the United Kingdom (Kapoor, R. et al. Eur J Endocrinol 168(4):557-564, 2013), KCNJ11 mutations identified via DNA sequencing were found in 10 out of 105 (9.5%) diazoxide-nonresponsive CHI patients including 6 patients with homozygous mutations and 4 patients affected by focal disease with a paternally inherited mutation. Only one of 183 diazoxide-responsive CHI patients had a heterozygous dominant KCNJ11 mutation.

See More

See Less

Deletion/Duplication Testing via aCGH

Test Code Test Copy GenesIndividual Gene PriceCPT Code Copy CPT Codes
600 KCNJ11$990.00 81479 Add to Order
Pricing Comment

# of Genes Ordered

Total Price









Over 100

Call for quote

Turnaround Time

The great majority of tests are completed within 20 days.

Clinical Features

Congenital hyperinsulinism (CHI) is a clinically and genetically heterogeneous condition characterized by hypoglycemia (Glaser, B. et al. GeneReviews, 2003; Arnoux, J.B. et al. Early Hum Dev 86(5):287-294, 2010). The age of disease onset ranges from the neonatal period with severe forms to infancy or childhood with milder forms. Severe patients typically have extremely low serum glucose while milder cases present with variable hypoglycemia. Affected newborns also develop nonspecific symptoms including seizures, apnea, hypotonia, and poor feeding. Severity of disease manifestations can vary within the same family.


CHI is genetically caused by defects in genes involved in regulation of insulin secretion from pancreatic beta-cells (Kapoor, R. et al. Eur J Endocrinol 168(4):557-564, 2013; Snider, K. et al. J Clin Endocrinol Metab 98(2):E355-563, 2013). KCNJ11-related congenital hyperinsulinism can be inherited in an autosomal recessive or dominant manner. KCNJ11 is a single exon gene that encodes the Kir6.2 subunit of the ATP-sensitive potassium (KATP) channels in beta-cells. Genetic defects located throughout the KCNJ11 gene include missense, nonsense, regulatory, and small deletion/insertions (Human Gene Mutation Database). While CHI patients with recessive KCNJ11 mutations are medically unresponsive to the KATP channel agonist diazoxide, dominant KCNJ11 mutations are exclusively associated with diazoxide-responsive patients (Kapoor, R. et al., 2013; Snider, K. et al., 2013).

Other genes have also been associated with CHI including ABCC8 (the other KATP gene), GLUD1, GCK, HADH, SLC16A1, HNF4A, HNF1A and UCP2 (Kapoor, R. et al., 2013; Snider, K. et al., 2013; González-Barroso, M. et al. PLoS One 3(12):e3850, 2008).

Testing Strategy

Testing is accomplished by amplifying the single exon of the KCNJ11 gene and ~120 bp upstream of the start codon, then determining the nucleotide sequence using standard dideoxy Sanger sequencing methods and a capillary electrophoresis instrument. We will also sequence any single portion of the exon (Test #100) or portions of the exon (Test #200) in family members of patients with known mutations or to confirm research results.

Parental targeted testing for all probands with uncertain, likely pathogenic or pathogenic variants in the KCNJ11 gene are free of charge.

Indications for Test

Candidates for this test are patients with CHI, especially diazoxide-nonresponsive patients. Testing is also indicated for family members of patients who have known KCNJ11 mutations.


Official Gene Symbol OMIM ID
KCNJ11 600937
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT


Name Inheritance OMIM ID
Hyperinsulinemic Hypoglycemia, Familial, 2 601820


Genetic Counselors
  • Arnoux J.B. et al. 2010. Early Human Development. 86: 287-94. PubMed ID: 20550977
  • Glaser B. 2003. Familial Hyperinsulinism. In: Pagon RA, Adam MP, Ardinger HH, Bird TD, Dolan CR, Fong C-T, Smith RJ, and Stephens K, editors. GeneReviews(®), Seattle (WA): University of Washington, Seattle. PubMed ID: 20301549
  • González-Barroso M.M. et al. 2008. Plos One. 3: e3850. PubMed ID: 19065272
  • Human Gene Mutation Database (Bio-base).
  • Kapoor R.R. et al. 2013. European Journal of Endocrinology / European Federation of Endocrine Societies. 168: 557-64. PubMed ID: 23345197
  • Snider K.E. et al. 2013. The Journal of Clinical Endocrinology and Metabolism. 98: E355-63. PubMed ID: 23275527
Order Kits

Bi-Directional Sanger Sequencing

Test Procedure

Nomenclature for sequence variants was from the Human Genome Variation Society (  As required, DNA is extracted from the patient specimen.  PCR is used to amplify the indicated exons plus additional flanking non-coding sequence.  After cleaning of the PCR products, cycle sequencing is carried out using the ABI Big Dye Terminator v.3.0 kit.  Products are resolved by electrophoresis on an ABI 3730xl capillary sequencer.  In most cases, sequencing is performed in both forward and reverse directions; in some cases, sequencing is performed twice in either the forward or reverse directions.  In nearly all cases, the full coding region of each exon as well as 10 bases of non-coding DNA flanking the exon are sequenced.

Analytical Validity

As of February 2018, we compared 26.8 Mb of Sanger DNA sequence generated at PreventionGenetics to NextGen sequence generated in other labs. We detected only 4 errors in our Sanger sequences, and these were all due to allele dropout during PCR. For Proficiency Testing, both external and internal, in the 14 years of our lab operation we have Sanger sequenced roughly 14,300 PCR amplicons. Only one error has been identified, and this was an error in analysis of sequence data.

Our Sanger sequencing is capable of detecting virtually all nucleotide substitutions within the PCR amplicons. Similarly, we detect essentially all heterozygous or homozygous deletions within the amplicons. Homozygous deletions which overlap one or more PCR primer annealing sites are detectable as PCR failure. Heterozygous deletions which overlap one or more PCR primer annealing sites are usually not detected (see Analytical Limitations). All heterozygous insertions within the amplicons up to about 100 nucleotides in length appear to be detectable. Larger heterozygous insertions may not be detected. All homozygous insertions within the amplicons up to about 300 nucleotides in length appear to be detectable. Larger homozygous insertions may masquerade as homozygous deletions (PCR failure).

Analytical Limitations

In exons where our sequencing did not reveal any variation between the two alleles, we cannot be certain that we were able to PCR amplify both of the patient’s alleles. Occasionally, a patient may carry an allele which does not amplify, due for example to a deletion or a large insertion. In these cases, the report contains no information about the second allele.

Similarly, our sequencing tests have almost no power to detect duplications, triplications, etc. of the gene sequences.

In most cases, only the indicated exons and roughly 10 bp of flanking non-coding sequence on each side are analyzed. Test reports contain little or no information about other portions of the gene, including many regulatory regions.

In nearly all cases, we are unable to determine the phase of sequence variants. In particular, when we find two likely causative mutations for recessive disorders, we cannot be certain that the mutations are on different alleles.

Our ability to detect minor sequence variants, due for example to somatic mosaicism is limited. Sequence variants that are present in less than 50% of the patient’s nucleated cells may not be detected.

Runs of mononucleotide repeats (eg (A)n or (T)n) with n >8 in the reference sequence are generally not analyzed because of strand slippage during PCR and cycle sequencing.

Unless otherwise indicated, the sequence data that we report are based on DNA isolated from a specific tissue (usually leukocytes). Test reports contain no information about gene sequences in other tissues.

Deletion/Duplication Testing via Array Comparative Genomic Hybridization

Test Procedure

Equal amounts of genomic DNA from the patient and a gender matched reference sample are amplified and labeled with Cy3 and Cy5 dyes, respectively. To prevent any sample cross contamination, a unique sample tracking control is added into each patient sample. Each labeled patient product is then purified, quantified, and combined with the same amount of reference product. The combined sample is loaded onto the designed array and hybridized for at least 22-42 hours at 65°C. Arrays are then washed and scanned immediately with 2.5 µM resolution. Only data for the gene(s) of interest for each patient are extracted and analyzed.

Analytical Validity

PreventionGenetics' high density gene-centric custom designed aCGH enables the detection of relatively small deletions and duplications within a single exon of a given gene or deletions and duplications encompassing the entire gene. PreventionGenetics has established and verified this test's accuracy and precision.

Analytical Limitations

Our dense probe coverage may allow detection of deletions/duplications down to 100 bp; however due to limitations and probe spacing this cannot be guaranteed across all exons of all genes. Therefore, some copy number changes smaller than 100-300 bp within a targeted large exon may not be detected by our array.

This array may not detect deletions and duplications present at low levels of mosaicism or those present in genes that have pseudogene copies or repeats elsewhere in the genome.

aCGH will not detect balanced translocations, inversions, or point mutations that may be responsible for the clinical phenotype.

Breakpoints, if occurring outside the targeted gene, may be hard to define.

The sensitivity of this assay may be reduced when DNA is extracted by an outside laboratory.

Order Kits

Ordering Options

myPrevent - Online Ordering
  • The test can be added to your online orders in the Summary and Pricing section.
  • Once the test has been added log in to myPrevent to fill out an online requisition form.
  • A completed requisition form must accompany all specimens.
  • Billing information along with specimen and shipping instructions are within the requisition form.
  • All testing must be ordered by a qualified healthcare provider.


(Delivery accepted Monday - Saturday)

  • Collect 3 ml -5 ml (5 ml preferred) of whole blood in EDTA (purple top tube) or ACD (yellow top tube). For Test #500-DNA Banking only, collect 10 ml -20 ml of whole blood.
  • For small babies, we require a minimum of 1 ml of blood.
  • Only one blood tube is required for multiple tests.
  • Ship blood tubes at room temperature in an insulated container. Do not freeze blood.
  • During hot weather, include a frozen ice pack in the shipping container. Place a paper towel or other thin material between the ice pack and the blood tube.
  • In cold weather, include an unfrozen ice pack in the shipping container as insulation.
  • At room temperature, blood specimen is stable for up to 48 hours.
  • If refrigerated, blood specimen is stable for up to one week.
  • Label the tube with the patient name, date of birth and/or ID number.


(Delivery accepted Monday - Saturday)

  • Send in screw cap tube at least 5 µg -10 µg of purified DNA at a concentration of at least 20 µg/ml for NGS and Sanger tests and at least 5 µg of purified DNA at a concentration of at least 100 µg/ml for gene-centric aCGH, MLPA, and CMA tests, minimum 2 µg for limited specimens.
  • For requests requiring more than one test, send an additional 5 µg DNA per test ordered when possible.
  • DNA may be shipped at room temperature.
  • Label the tube with the composition of the solute, DNA concentration as well as the patient’s name, date of birth, and/or ID number.
  • We only accept genomic DNA for testing. We do NOT accept products of whole genome amplification reactions or other amplification reactions.


(Delivery preferred Monday - Thursday)

  • PreventionGenetics should be notified in advance of arrival of a cell culture.
  • Culture and send at least two T25 flasks of confluent cells.
  • Some panels may require additional flasks (dependent on size of genes, amount of Sanger sequencing required, etc.). Multiple test requests may also require additional flasks. Please contact us for details.
  • Send specimens in insulated, shatterproof container overnight.
  • Cell cultures may be shipped at room temperature or refrigerated.
  • Label the flasks with the patient name, date of birth, and/or ID number.
  • We strongly recommend maintaining a local back-up culture. We do not culture cells.
loading Loading... ×