Understanding Disorders with Autism-Like Traits: Fragile X & Down Syndrome

* Fragile X syndrome: A genetic condition that is the most common known cause of inherited intellectual disability. It is caused by a mutation in the FMR1 gene, which is located on the X chromosome. Fragile X syndrome can cause a range of symptoms, including intellectual disability, autism-like behaviors, hyperactivity, and attention deficit disorder.

* Down syndrome: A genetic disorder caused by the presence of an extra copy of chromosome 21. Down syndrome can cause a range of symptoms, including intellectual disability, autism-like behaviors, short stature, and distinctive physical features.

* Rett syndrome: A neurodevelopmental disorder that affects girls almost exclusively. It is caused by a mutation in the MECP2 gene, which is located on the X chromosome. Rett syndrome can cause a range of symptoms, including intellectual disability, autism-like behaviors, hand stereotypies, and seizures.

* Angelman syndrome: A neurodevelopmental disorder that is caused by a deletion or mutation of the UBE3A gene, which is located on chromosome 15. Angelman syndrome can cause a range of symptoms, including intellectual disability, autism-like behaviors, seizures, and sleep problems.

* Phelan-McDermid syndrome: A genetic disorder that is caused by a deletion or mutation of the SHANK3 gene, which is located on chromosome 22. Phelan-McDermid syndrome can cause a range of symptoms, including intellectual disability, autism-like behaviors, speech and language problems, and seizures.