Early-onset generalized torsion dystonia (DYT1)

What happens in this disease?

A change in a gene called TOR1A disrupts communication between the nerve cells that control movement. As a result, the muscles contract involuntarily; this is called dystonia. Symptoms usually begin in one arm or leg. In some people, they spread over time to the trunk and to the other arms and legs.

Which symptoms can occur?

Symptoms usually begin in childhood or the teenage years. They differ greatly from person to person, even within the same family.

• Involuntary contraction and twisting of an arm or leg (a common first symptom)
• Cramping of the hand while writing, called writer's cramp
• The foot turning inward when walking
• Movements continuing over time even at rest (sometimes)
• Contractions spreading to the trunk and the other limbs (sometimes)
• Tremor

How is it diagnosed?

The diagnosis is suspected from a neurological examination. A genetic test shows the change in the TOR1A gene. There is usually no visible structural problem in the brain.

Treatment and care

Treatment aims to ease the symptoms. A movement disorder specialist becomes involved early on. Medicine and deep brain stimulation, a surgery to place a brain pacemaker, are among the options. Physiotherapy and occupational therapy make daily tasks easier. Regular follow-up is important. The doctor who follows the disease decides which treatment is suitable.

For the family: inheritance and genetic counselling

The disease is passed on through dominant inheritance. For each child of a parent with the gene change, the chance of inheriting the gene is 1 in 2. But only about one third of those who inherit the gene develop the disease. Severity can differ within the same family. Genetic counselling explains the risks to the family.