alt Comparison of ECGs from a single family showing unaffected family member (top), Romano-Ward<unk>  (middle) and<unk>  (bottom)The sensorineural hearing loss in<unk>  is present from birth and can be diagnosed using audiometry or physiological tests of hearing. The cardiac features of<unk>  can be diagnosed by measuring the QT interval corrected for heart rate (QTc) on a 12-lead electrocardiogram (ECG). The QTc is less than 450 ms in 95% of normal males, and less than 460 ms in 95% of normal females. In those with<unk>  the QTc is typically greater than 500 ms. Other factors beyond the QT interval should be taken into account when making a diagnosis, some of which have been incorporated into scoring systems such as the Schwartz score. These factors include a history of characteristic abnormal heart rhythms (Torsades de Pointes), unexplained blackouts (syncope), and a family history of confirmed LQT<unk> . Genetic testing to identify variants in the KCNQ1 or KCNE1 genes can also be used.
Jervell and Lange-Nielsen syndrome
Long QT syndrome
Fox–Fordyce disease
Andersen–Tawil syndrome
Laron syndrome
Cowden syndrome
Koolen–De Vries syndrome
Prader–Willi syndrome