Balanced translocation linked to psychiatric disorder, glutamate, and cortical structure/function.

Area of Science:

• Neurogenetics
• Psychiatric Disorders
• Brain Imaging

Background:

• Rare genetic variants with large effects aid in understanding brain disorder pathophysiology.
• A family with a (1;11)(q42;q14.3) translocation presented with multiple affected individuals and major psychiatric illnesses.

Purpose of the Study:

• To analyze the clinical and genetic aspects of the (1;11)(q42;q14.3) translocation.
• To investigate the translocation's impact on prefrontal and temporal brain structure and function.
• To identify correlations between the translocation and specific psychiatric symptoms.

Main Methods:

• Family-based linkage analysis (LOD score 6.1) to associate the translocation with psychiatric phenotypes.
• Neuroimaging techniques to assess cortical thickness and gyrification in translocation carriers.
• Functional neuroimaging (fMRI) to evaluate brain activation during working memory tasks.
• Magnetic resonance spectroscopy (MRS) to measure glutamate concentrations in specific brain regions.

Main Results:

• The t(1;11) translocation showed significant linkage with a phenotype including schizophrenia, schizoaffective disorder, bipolar disorder, and major depressive disorder.
• Translocation carriers exhibited reduced left temporal lobe cortical thickness and prefrontal cortex gyrification, correlating with psychopathology severity.
• Increased caudate nucleus activation during verbal working memory and reduced right dorsolateral prefrontal cortex glutamate concentrations were observed in carriers.

Conclusions:

• The t(1;11) translocation is confirmed to significantly increase the risk for major psychiatric disorders.
• Altered cortical structure, impaired brain function, and decreased glutamate levels suggest a general vulnerability to psychopathology conferred by the translocation.