Special Notice

Our website is undergoing changes and some listed testing may not be available any longer.  Except for Amish targeted testing and GAP testing, please call prior to ordering to be sure a test is available.


DDC Clinic
Molecular Diagnostics Laboratory

Telephone: 440-632-5532
e-mail: lab@ddcclinic.org

CLIA: 36D1001860
Tax ID: 34-1914344

Long QT Syndrome 1 (KCNQ1) Targeted Testing

Long QT Syndrome 1 (KCNQ1) Targeted Testing

Short Name:
KCNQ1 Targeted
Targeted Testing Price:
Targeted Testing CPT:
Gene Name(s):
General Information:

Congenital long QT syndrome (LQTS) is a rare heart condition characterized by a prolonged QT interval on ECG/EKG and polymorphic ventricular arrhythmias (torsade de pointes). These cardiac arrhythmias may result in recurrent syncope, seizure, or sudden death. Variants in various genes encoding ion channels are associated with different forms of LQTS. The long QT syndrome 1 (LQT1) is caused by variants in the KCNQ1 gene. LQT1 can be inherited in both autosomal dominant and autosomal recessive patterns. Autosomal dominant LQT1 is manifested with variable penetrance.

A 2-bp deletion, c.451_452delCT (p.Leu151Glyfs), in exon 2 of the KCNQ1 gene is the most frequent pathogenic variant found in Amish patients. The homozygous c.451_452delCT variant has been reported in Old Order Amish patients with long QT syndrome and deafness. Heterozygous variants in the KCNQ1 gene have been reported in familial long QT syndrome patients with no hearing loss. This targeted test will specifically analyze the c.451_452delCT variant.

  • Specimen Requirements

    Label specimens with the patient’s full name, date of birth, collection date and source (if appropriate). Please use the tube size appropriate for the sample volume.

    Peripheral Blood

    • Infants: Minimum of 2-3 ml of whole blood in a purple top (EDTA) tube.
    • Adults and children over 2 years of age: Minimum of 3-5 ml of whole blood in a purple top (EDTA) tube.

    Cord Blood

    • Minimum of 3-5 ml of whole blood in a purple top (EDTA) tube.

    Isolated DNA

    • Minimum of 50 µl at a concentration of 100 ng/µl. Please include concentration on the specimen label.
  • Storage and Shipping Information

    Blood samples are stable at room temperature (15ºC to 25ºC) for one day or at 2º to 8ºC for up to 5 days. Blood samples should not be frozen at any time.

    DNA sample stability is dependent on the methodology used for the isolation. In general the DNA should be stable and can be shipped ambient or cold, following the directions below.

    Specimens from outside facilities should be packaged according to standard medical safety practices. Refrigerate samples if stored overnight prior to shipping. In hot weather, include a cool pack in the shipping container. Do not allow the specimen to freeze at any time. Package the completed test requisition inside the packaging container with the specimen. Please ship by overnight priority.

    Specimens should not be shipped on Fridays, Saturdays or the day preceding a holiday.

    **Holiday schedules will be noted on our website at least one week prior to the holiday. Feel free to contact us with any questions.

Shipping Address:

DDC Clinic Molecular Diagnostics Laboratory
14567 Madison Rd
Middlefield OH 44062

Contact Information:

Telephone: 440-632-5532
Fax: 440-632-1697
Email: lab@ddcclinic.org

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