What syndrome is characterized by mental impairment and physical features such as a long face and large ears?

Fragile X syndrome is characterized by mental impairment, including developmental delays and cognitive disabilities, as well as distinctive physical features such as an elongated face and prominent ears. This genetic condition is caused by a mutation in the FMR1 gene on the X chromosome, which leads to the silencing of a key protein necessary for normal brain development.

Individuals with Fragile X often exhibit social and behavioral issues, such as anxiety and autism spectrum disorders, alongside the recognizable physical traits. The distinctive facial appearance and the association with intellectual disability make it easier to differentiate Fragile X syndrome from other syndromes listed.

In contrast, Turner syndrome primarily affects females and is characterized by short stature and lack of ovarian development, rather than the cognitive impairments or specific facial features seen in Fragile X. Prader-Willi syndrome also has cognitive aspects but is more known for features like obesity, hyperphagia, and hypothalamic dysfunction rather than the distinctive facial characteristics. Lepin mutation is not widely recognized as a syndrome linked with specific cognitive or physical features in the same manner as the others.