Your personalized genetics report.

Pathogenic Test Report

What is a pathogenic KCNQ1 result?

A pathogenic result means that a DNA change (variant) was found in the KCNQ1 gene which causes disease (pathogenic). If a person has a specific change (variant) in a gene called KCNQ1, it is considered to be related to a disease called long QT syndrome (LQTS).

What does this mean?

  • Long QT syndrome (LQTS) is a heart condition (cardiac electrophysiologic disorder) that causes the electrical signals in the heart to take longer than normal to travel from the top to bottom (QT prolongation) and seen as abnormal wave patterns on an electrocardiogram (EKG). This can cause an irregular heartbeat (tachyarrhythmias), usually in the form of a fast, twisting heart rhythm (torsade de pointes or TdP).
  • Cardiac events like heart problems (cardiac events) often happen during physical activity (exercise) and when a person is feeling strong emotions (emotional stress). They may also happen less frequently while a person is sleeping, and usually without any warning signs.
  • In some cases, TdP can cause the heart to beat in an abnormal way (ventricular fibrillation). This can cause the heart to stop beating (cardiac arrest) if the person is shocked with a defibrillator or can lead to sudden death.
  • Heart-related problems (cardiac events) can happen to people of any age, but are most likely to happen between the ages of preteens and 20s.
  • Most people with this condition can lead normal lives if they stick to their medication.
  • It is important to educate adult individuals and the parents of children with the condition about how to properly take the medication as part of their management

Family.

How does this affect my family?

  • Variations in the KCNQ1 gene can be passed down from parent to child (inherited) or a person may be the first in the family to have a new variation (variant) in their KCNQ1 gene.
  • Brothers and sisters and other family members may also have this change in the KCNQ1 gene.
  • People with a DNA change in the KCNQ1 gene can pass it on to their children.

What you can do:

Next Steps.

Your provider will first figure out how severe the condition is and what needs you have. The main goal of the care plan is to identify the people who are most at risk for heart-related issues.

Evaluating your risk:

1. EKG

  • An EKG is a test that looks at the electrical activity of the heart (electrocardiogram or ECG). It is done to check for any abnormalities or problems with the heart.

2. Overt T-wave alternanas

  • People with a certain measurement of the heartbeat (QTc interval) that >500 ms have an increased risk of a medical event.
  • People with a QTc interval >600 ms have an extremely high risk of a medical event.
  • Overt T-wave alternans is a change in the electrical activity of the heart (T-wave) that is visible on an electrocardiogram. When this occurs when a patient is taking beta blockers, it is associated with a higher risk of heart related events.

3. Medical history

  • People with a sudden loss of consciousness (syncope) or a temporary stopping of the heart (cardiac arrest) in the first year of life or younger than seven years old are at higher risk for this condition.
  • These people may not be completely protected (fully protected) from a medical treatment (pharmacologic treatment).
  • People who have irregular heartbeats (arrhythmic events) while taking medication to treat them (pharmacologic treatment) have a higher risk of something happening to them.

Care Plan.

All people with symptoms of the condition should be treated. Treatment focuses on preventing syncope (fainting), cardiac arrest (heart stopping) and sudden death.

1. EKG Monitoring

  • Low risk patients with QTc <500 ms receive baseline EKG monitoring annually. 
  • High risk patients with QTc > 500 ms should receive EKG monitoring every 3 days or as recommended by your provider.

2. Take Beta Blockers daily. 

  • Beta blockers are the main type of treatment for a condition called long QT syndrome (LQTS).
  • Most of the heart events that occur in people with long QT syndrome who are taking medications to treat their condition (beta blockers) are not caused by the medication not working, but by the patient not taking the medication (non-compliance) or taking medications that can make the QT interval longer (QT-prolonging drugs).
  • It is important to make sure children get the right dose of beta blockers (medicines that slow down the heart rate) regularly so it can be effective (adequate dosing). This should be done by checking the heart rate when the patient is exercising (exercise EKG) or by a heart rate monitor worn for a period of time (ambulatory EKG).
  • Beta blockers should be taken every day and have a plan in place in case of missed doses. Long-acting medicines (nadolol) should be used to make sure patients take their medicine correctly and should avoid short-acting medicines (metoprolol).

3. Implantable cardioverter-defibrillators (ICDs)

  • ICDs are small medical devices used to help treat patients who do not respond well to beta-blocker medications or for those taking other medications that can’t be taken with beta-blockers (such as severe asthma).

4. Left cardiac sympathetic denervation (LCSD) 

  • LCSD may be used in high-risk patients that can not take beta blockers and can not have an ICD implanted in their chest.

5. Sodium channel blockers

  • drugs used to treat people who have a longer than usual time between heartbeats (QTc interval 500 ms). This drug can help shorten the time between heartbeats by more than 40 ms (QTc interval 40 ms). 

Avoid:

1. Drugs that increase the time it takes for the heart to recharge between beats (QT interval) or cause a type of abnormal heart rhythm (torsade de pointes) should be avoided for people with Long QT Syndrome (LQTS). Ask your doctor about which drugs to avoid.

2. Epinephrine, a medication given with local anesthetics, can cause abnormal heart rhythms (arrhythmias) so it is best to not use it.

3. Electrolyte imbalances in the body can cause the QTc interval to become longer. It is important to identify and fix any electrolyte imbalances to prevent this from happening. Imbalances in the body can happen due to having diarrhea, throwing up (vomiting), medical conditions (metabolic conditions) or eating an unhealthy diet to try and lose weight (unbalanced diets for weight loss).

4. Vigorous exercise – especially swimming without someone watching – to stay safe. People should have their risk evaluated by a medical expert before participating in competitive sports.

5. Loud noises – recommended to reduce exposure to loud noises like alarm clocks and phone ringing.

6. Stress, anger or crying