What percent of people have long QT?

What percent of people have long QT?

When the Q-T interval is longer than normal, it increases the risk for torsade de pointes, a life-threatening form of ventricular tachycardia. LQTS is rare. The prevalence is about 1 in 5,000 persons in the United States.

How is long QT syndrome inherited?

Typically, the mutation is inherited from or “carried” by a parent. Long QT syndrome also shows variable expressivity and incomplete penetrance. In autosomal dominant disorders this means that manifestations of the disorder may not be present in all those who inherit the same altered gene for the disease.

What is Type 2 long QT syndrome?

Long QT syndrome type 2 is a life-threatening disorder of cardiac electrophysiology. It can lead to sudden cardiac death as a result of QT prolongation and can remain undetected until it presents clinically in the form of life-threatening cardiac arrythmias.

How common is LQT2?

LQT2 represents about 35% of cases, and LQT3 less than 5% of cases. The other forms are quite rare. The autosomal dominant forms of LQT syndrome are responsible for the majority of cases.

What causes Timothy syndrome?

Mutations in the CACNA1C gene are responsible for all reported cases of Timothy syndrome. This gene provides instructions for making a protein that acts as a small hole or pore (a channel ) across cell membranes. This channel, known as CaV1.

What is Pendred syndrome?

Pendred syndrome is a disorder typically associated with hearing loss and a thyroid condition called a goiter. A goiter is an enlargement of the thyroid gland , which is a butterfly-shaped organ at the base of the neck that produces hormones.

What is normal QTc range?

The electrocardiographic QTc is approxi- mately normally distributed in the general population. Normal values for the QTc range from 350 to 450 ms for adult men and from 360 to 460 ms for adult women; however, 10%-20% of oth- erwise healthy persons may have QTc values outside this range.