Autosomal dominant
Caused by changes in the TET3 gene, which removes methyl marks from DNA. Most people have a new change in one copy, though inherited changes occur, including from a mildly affected parent. The condition is inherited in an autosomal dominant way with variable expressivity.
Signs and symptoms
Developmental delay and intellectual disability of variable degree, low muscle tone and behavioural differences, including autism, are common. Overgrowth is more common than undergrowth, with a large head the most common growth change, and facial features are typically subtle. Epilepsy occurs in about a third of people, and movement disorders and feeding difficulties can also occur.
What a diagnosis changes
Developmental, educational and behavioural support, with growth and neurological review and treatment of seizures when present. Because inheritance can be from a new change or from a parent, genetic counselling with testing of parents helps clarify recurrence risk.
Genes analysed
Also known as
BEFAHRS
