Endocrine Abstracts

JOINT508

Background: Turner Syndrome (TS), a chromosomal disorder resulting from partial or complete monosomy of the X chromosome, affects multiple organ systems, including the brain. TS is characterized by distinct neurocognitive and structural abnormalities, including deficits in visuospatial abilities, social cognition, and memory, along with morphological changes in specific brain regions. Understanding these changes through neuroimaging is critical for improving diagnosis and targeted interventions.

Methods: A systematic review of 15 neuroimaging studies was conducted, encompassing 696 patients with TS, ranging from children to adults, and 641 matched controls. Studies utilized multimodal MRI techniques, including volumetric analysis, diffusion tensor imaging, and surface-based morphometry. Key outcomes assessed included regional brain volume, cortical thickness, white matter integrity, and functional connectivity.

Results: Neuroimaging studies consistently demonstrated structural and functional alterations in TS. Common findings included:.

• Amygdala and hippocampus: In 30 TS patients, increased left amygdala volume and reduced right hippocampal volume were observed, which correlated with social cognition and memory deficits.

• Parietal regions: Aberrant growth trajectories of white and gray matter were evident, especially in the left superior parietal regions, linked to visuospatial impairments.

• Cortical structure: Smaller cortical surface area and increased cortical thickness were predominant in TS patients, with regional differences in the pericalcarine, postcentral, and parietal areas.

• White matter networks: Reduced topological efficiency of hemispheric white matter connectivity was observed, particularly in the parietal modules, impairing working memory.

• Functional connectivity: Intrinsic connectivity disruptions in regions involved in math-related cognition and visuospatial processing were identified.

Across studies, the role of X chromosome haploinsufficiency, hormonal deficiencies (notably estrogen), and genomic imprinting were underscored as key contributors to these neurodevelopmental anomalies.

Discussion: These findings highlight the interplay of genetic and hormonal factors in shaping brain development in TS. The identified structural abnormalities have direct implications for neurocognitive deficits, particularly in visuospatial, social, and memory domains. The data suggest the importance of early diagnosis and tailored interventions, including hormonal replacement therapy, to mitigate neurodevelopmental challenges.

Conclusion: Consistent neuroimaging findings show that Turner Syndrome profoundly impacts brain structure and function. A comprehensive understanding of these alterations can guide improved therapeutic strategies, enhancing the quality of life for individuals with TS. Future research should focus on longitudinal studies to track developmental trajectories and the impact of interventions.