Changes with Age
Changes in intellectual disability
Research has shown that there is a decline in IQ scores as individuals with FXS get older. This occurs in nearly all males with fragile X syndrome.
However, it is important to note that this ‘decline’ in IQ reflects a slower rate of intellectual development in individuals with fragile X syndrome than in typically developing children rather than an actual loss of IQ. This means that IQ remains stable or improves but the gap between individuals with fragile X syndrome and typically developing children increases.
The rate of this decline appears to be related to the genetic makeup of FXS and so, will largely depend on the individual. For example, a study by Dr. Scott Hall and his team showed that IQ score decline could range from 4 to 9 points over a period ranging from several months up to 13 years.
To read more about intellectual characteristics in fragile X syndrome, click here.
Changes in adaptive functioning
At around 10-12 years a high proportion of boys with fragile X syndrome show a plateau in the development of adaptive behaviour skills. There is also some evidence that at this age around half of boys with fragile X syndrome show a decline in socialisation skills and adaptive communication. This decline may be related to the increase of social anxiety that is observed in adolescence. More able individuals and those who show fewer autistic-like traits are more likely to have better adaptive functioning.
To read more about adaptive skills in individuals with fragile X syndrome, click here.
Changes in autistic characteristics
For some people with fragile X syndrome, there is some evidence that characteristics of autism become less severe with age. However, this is based on a very small number of studies and the changes were only slight. One study showed that 13% of individuals with FXS who previously had a dual diagnosis of autism, no longer met the criteria for an autism diagnosis later in life. The main improvements were reported in gestures and social skills.
Despite this, other studies have found a different pattern with increased severity of social-emotional difficulties with age. Much more research into changes with age needs to be conducted.