Triple-X syndrome
What are the symptoms?
The effect of having an extra X chromosome can be very varied. Some females with triple-X syndrome show no, or very few, symptoms and are entirely 'normal', whilst others have learning difficulties, developmental delay and/or behavioural problems. Individuals may show some or all features and furthermore may be differently affected by the severity of their symptoms. It is not possible to offer a precise prediction of the symptoms either before or even immediately after the birth of each triple-X girl.
At birth, girls with triple-X are usually normally developed, although babies may be floppy (hypotonic) and weight may be slightly lower than average. Many girls have a 'growth spurt' up until the age of eight years and women tend to be a little taller than average. In the 'full blown' condition, girls with triple-X are at risk of delays in neuromotor development, learning ability and/or impaired psychosocial adaptation. This leads to co-ordination problems including both gross motor skills and/or fine motor skills.
Delays in speech and language development are frequent but individuals respond well to speech therapy. Behavioural problems including tantrums, shyness and emotional immaturity are rather more frequent than in girls with XX chromosomes.
Sexual development is normal and triple-X women are fertile though there is a slight increased risk of sex chromosome changes in their children and an amniocentesis test is available to confirm this. Some women have been reported to have an early menopause, however further follow-up studies are required to confirm how likely this is for the majority of triple-X women. Individuals with triple-X have no increased risk of any diseases during childhood or in adult life.
Background
| How is it treated? ![]()