How Is Fragile X Syndrome Linked to Autism?

13:28 29th August 2018 | Genetic Defects

How Is Fragile X Syndrome Linked to Autism?

Fragile X syndrome (FXS) is an inherited genetic disorder that may cause learning and behavioural challenges and is often characterised by large ears or a long face. It is caused by a mutation on the FMR1 gene on the X chromosome, which affects the production of a certain protein. An absence of this protein causes the characteristic symptoms of FXS.

As females have two copies of the X chromosome, they are far less likely to inherit the disorder.

What are the characteristics of FXS:

Behavioural traits include attention deficit disorder, varying levels of autism, social anxiety, poor eye contact, and imitation
Mild to severe intellectual disability and learning disabilities
Repetitive behaviours, such as hand-flapping

FXS and autism:

FXS is the most common genetic cause of autism spectrum disorder (ASD). ASD is a cluster of symptoms which is usually characterised by the inability to communicate or interact socially with other people.

Many individuals with FXS but not ASD are still very sociable, are acutely aware of their surroundings, and have a great memory and sense of humour. If you are aware that FXS runs in your family, genetic testing is recommended should you wish you have children.