Autosomal dominant
Caused by gain-of-function changes in one copy of KCNH1, a potassium channel in nerve cells. De novo variants are associated with epileptic encephalopathy, while inherited or mosaic variants have been linked to isolated epilepsy or febrile seizures.
Signs and symptoms
Developmental delay, intellectual disability and epilepsy are common. Thumb and skeletal anomalies, and nail hypoplasia or aplasia, are reported. Facial dysmorphism is also a feature.
What a diagnosis changes
Seizure management by a neurologist, developmental and educational support. Genetic counselling and parental testing guide recurrence risk.
Genes analysed
Includes 2 related subtypes ↓Hide subtypes ↑
- Temple-Baraitser syndrome
- Zimmermann-Laband syndrome 1
MONDO:0100485Sources: [1][2][3]
