There is no single cause of stammering, nor a simple cure. Some children seem to have inherited a vulnerability to stammering, but it is not always easy to trace a family history.
Usually, children show signs of stammering around three years old. While the research suggests that four out of five of these children will recover spontaneously, it is really important to see those children who are at risk of a persisting problem as soon as possible.
Early intervention is effective. The longer a child has been stammering, the more entrenched the problem becomes – and therefore therapy will take longer. Therapy for a young child is a partnership between the speech and language therapist and the parents, in understanding what their individual child needs to enhance and develop increasing levels of natural fluency in everyday situations.
The study's findings emphasise that stammering has biological causes in some cases. Although the symptoms can be affected by emotional factors (like anxiety), it is not a social, emotional or psychological disorder. The study reinforces our knowledge that parents do not cause stammering in their children – something they worry about.
The research also indicates that stammering has a genetic basis, located on chromosome 12. Usually these genes are involved in encoding an enzyme that assists in breaking down and recycling cellular components. The study found mutations in these genes in the group of people who stammer, but not in those who were typically fluent.
It is important to note that the researchers suggest this only relates to 9 per cent of the stammering population studied, and that further research is planned.
The writer is head of specialty at the Michael Palin Centre for Stammering Children