Surface- and voxel-based brain morphologic study in Rett and Rett-like syndrome with MECP2 mutation

Area of Science:

• Neuroscience
• Genetics
• Developmental Biology

Background:

• Rett syndrome (RTT) is a rare neurodevelopmental disorder, primarily caused by MECP2 mutations.
• RTT presents with developmental regression, epilepsy, and motor and behavioral deficits.
• Previous studies noted reduced brain volumes, but surface-based morphology in RTT is under-explored.

Purpose of the Study:

• To investigate quantitative surface- and voxel-based brain morphology in young children with RTT and RTT-like syndrome (RTT-l) carrying MECP2 mutations.
• To identify specific brain structural abnormalities associated with MECP2 mutations in RTT/RTT-l.

Main Methods:

• Acquired structural T1-weighted MRI scans from 7 female patients (mean age 5.2 years) with MECP2 mutations.
• Performed quantitative surface-based and voxel-based morphometric analyses.
• Compared brain morphology of RTT/RTT-l patients with age- and gender-matched controls.

Main Results:

• Significantly decreased total cerebellar volumes were observed in RTT/RTT-l patients compared to controls.
• No statistically significant differences were found in global cerebral cortical surface areas, cortical thickness, gyrification, or gray/white matter volumes.
• Regional cerebellar volume reduction is a key early brain abnormality in RTT/RTT-l.

Conclusions:

• Early brain abnormalities in RTT/RTT-l associated with MECP2 mutations include regionally decreased cerebellar volumes.
• Cerebellar volume reduction may be crucial for understanding the etiology of RTT and RTT-l.
• Further research into cerebellar function and development in RTT is warranted.