Brain development in Turner syndrome: a magnetic resonance imaging study

Area of Science:

• Neurogenetics
• Developmental Neuroscience
• Medical Imaging

Background:

• Turner syndrome (TS) is a genetic condition in females characterized by the absence of an X chromosome.
• TS is often associated with cognitive impairments and distinct brain volume variations.
• Understanding these neuroanatomical differences is crucial for managing TS-related challenges.

Purpose of the Study:

• To investigate brain morphological variations in Turner syndrome using high-resolution MRI.
• To explore the influence of the parental origin of the X chromosome on brain development in TS.
• To identify specific brain regions affected by X monosomy.

Main Methods:

• Acquisition of MRI brain scans from 26 girls with TS and 26 age- and gender-matched controls.
• Categorization of TS subjects based on maternal (Xm) or paternal (Xp) X chromosome inheritance.
• Rater-blind morphometric analyses to compare tissue volumes between groups and subgroups.

Main Results:

• Girls with TS showed reduced bilateral parietal gray matter and occipital white matter, alongside increased cerebellar gray matter.
• Subjects with a maternally inherited X chromosome (Xm) exhibited decreased occipital white matter and increased cerebellar gray matter compared to controls.
• No significant differences were observed between subjects with a paternally inherited X chromosome (Xp) and controls, nor between Xm and Xp subgroups.

Conclusions:

• X monosomy in Turner syndrome impacts posterior cerebral and cerebellar anatomy.
• Observed differences in Xm subgroups suggest a potential, though not definitively proven, role for genomic imprinting.
• Further research is warranted to elucidate the role of genomic imprinting in Turner syndrome's neurodevelopmental effects.