Endophenotypes of FOXP2: dysfunction within the human articulatory network.

Area of Science:

• Neurogenetics
• Cognitive Neuroscience
• Speech and Language Sciences

Background:

• The first gene linked to speech-language disorders, FOXP2, was identified in the KE family.
• Affected members exhibit structural and functional brain abnormalities, particularly in cortical-subcortical networks.
• Previous studies noted challenges with word repetition in individuals with developmental speech and language disorders.

Purpose of the Study:

• To investigate the neural correlates of nonword repetition in individuals with FOXP2 mutations.
• To examine brain activation patterns during a challenging language task in the KE family.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to scan four affected KE family members and four healthy controls.
• Participants repeated nonsense words aloud during the fMRI scanning session.

Main Results:

• KE family members showed severely impaired nonword repetition compared to controls.
• Reduced brain activation was observed in affected individuals in motor cortices, cerebellum, and basal ganglia.
• These brain regions are crucial for imitation and vocal learning of speech sound sequences.

Conclusions:

• Nonword repetition is a sensitive endophenotype for FOXP2 gene disruption.
• The study elucidates the neural basis of speech and language impairments associated with FOXP2 mutations.
• Findings provide insights into the genetic and neural underpinnings of human vocal learning.