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  • Test code: 02214
  • Turnaround time:
    10–21 calendar days (14 days on average)
  • Preferred specimen:
    3mL whole blood in a purple-top tube
  • Alternate specimens:
    DNA or saliva/assisted saliva
  • Sample requirements
  • Request a sample kit
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Invitae Short QT Syndrome Panel

Test description

This test is for individuals with a clinical diagnosis of short QT syndrome (SQTS). The primary Invitae Short QT Syndrome Panel includes five genes that are definitively associated with SQTS or other inherited arrhythmia disorders that can present with clinical features similar to SQTS.

Individuals with clinical symptoms of SQTS may benefit from diagnostic genetic testing to confirm diagnosis, clarify risks, or inform management. Asymptomatic members of a family with a known SQTS pathogenic variant may also benefit, as testing may clarify their own personal risk of developing SQTS or inform medical management.

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Primary panel (5 genes)

CACNA1C CACNB2 KCNH2 KCNJ2 KCNQ1

Add-on Preliminary-evidence Gene for Short QT Syndrome (1 gene)

Preliminary-evidence genes currently have early evidence of a clinical association with the specific disease covered by this test. Some clinicians may wish to include a gene which does not currently have a definitive clinical association, but which may prove to be clinically significant in the future. This gene can be added at no additional charge. Visit our Preliminary-evidence genes page to learn more.

CACNA2D1

Alternative tests to consider

Short QT syndrome can also be ordered as part of broader panels to test for arrhythmia disorders. Depending on the individual’s clinical and family history, one of these broader panels may be appropriate. Any of these broader panels can be ordered at no additional charge.

  • short QT syndrome (SQTS)
    • SQTS type 1 (SQTS1)
    • SQTS type 2 (SQTS2)
    • SQTS type 3 (SQTS3)

SQTS is a cardiac condition that primarily affects the electrical system of the heart. SQTS is defined by a shortened QT interval, a measure of the time it takes for an electrical signal to travel through the heart. This is measured on an electrocardiogram, also known as an ECG or EKG. Individuals with SQTS can develop irregular and rapid heart rhythms, originating from either the top (atrial) or bottom (ventricular) chambers of the heart. These abnormal heart rhythms can cause fainting, dizziness, seizure-like episodes, cardiac arrest, and/or sudden death in both children and adults. It may be an underlying cause of some cases of sudden infant death syndrome (SIDS).

This test covers all of the common genetic causes of SQTS. SQTS is a rare condition and the proportion of individuals with SQTS who carry a disease-causing pathogenic variant identifiable by genetic testing is unknown.

Short QT syndrome is an autosomal dominant condition.

The penetrance of SQTS is unknown.

While its exact prevalence is unknown, SQTS is rare.

This test may be considered for individuals with:

  • arrhythmia consistent with a diagnosis of SQTS
  • unexplained cardiac arrest

For links to published management guidelines for cardiology conditions, please refer to our Management guidelines page.

Assay and technical information

Invitae is a College of American Pathologists (CAP)-accredited and Clinical Laboratory Improvement Amendments (CLIA)-certified clinical diagnostic laboratory performing full-gene sequencing and deletion/duplication analysis using next-generation sequencing technology (NGS).

Our sequence analysis covers clinically important regions of each gene, including coding exons, +/- 10 base pairs of adjacent intronic sequence in the transcript listed below. In addition, analysis covers the select non-coding variants specifically defined in the table below. Any variants that fall outside these regions are not analyzed. Any specific limitations in the analysis of these genes are also listed in the table below.

Based on validation study results, this assay achieves >99% analytical sensitivity and specificity for single nucleotide variants, insertions and deletions <15bp in length, and exon-level deletions and duplications. Invitae's methods also detect insertions and deletions larger than 15bp but smaller than a full exon but sensitivity for these may be marginally reduced. Invitae’s deletion/duplication analysis determines copy number at a single exon resolution at virtually all targeted exons. However, in rare situations, single-exon copy number events may not be analyzed due to inherent sequence properties or isolated reduction in data quality. Certain types of variants, such as structural rearrangements (e.g. inversions, gene conversion events, translocations, etc.) or variants embedded in sequence with complex architecture (e.g. short tandem repeats or segmental duplications), may not be detected. Additionally, it may not be possible to fully resolve certain details about variants, such as mosaicism, phasing, or mapping ambiguity. Unless explicitly guaranteed, sequence changes in the promoter, non-coding exons, and other non-coding regions are not covered by this assay. Please consult the test definition on our website for details regarding regions or types of variants that are covered or excluded for this test. This report reflects the analysis of an extracted genomic DNA sample. In very rare cases, (circulating hematolymphoid neoplasm, bone marrow transplant, recent blood transfusion) the analyzed DNA may not represent the patient's constitutional genome.

Gene Transcript reference Sequencing analysis Deletion/Duplication analysis
CACNA1C NM_000719.6; NM_001129840.1
CACNA2D1 NM_000722.3
CACNB2 NM_201590.2
KCNH2 NM_000238.3
KCNJ2 NM_000891.2
KCNQ1 NM_000218.2