AUTHOR=Elias-Mas Andrea , Alvarez-Mora Maria Isabel , Caro-Benito Conxita , Rodriguez-Revenga Laia 

TITLE=Neuroimaging Insight Into Fragile X-Associated Neuropsychiatric Disorders: Literature Review

JOURNAL=Frontiers in Psychiatry

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2021.728952

DOI=10.3389/fpsyt.2021.728952

ISSN=1664-0640

ABSTRACT=<p><italic>FMR1</italic> premutation is defined by 55–200 CGG repeats in the Fragile X Mental Retardation 1 (<italic>FMR1</italic>) gene. <italic>FMR1</italic> premutation carriers are at risk of developing a neurodegenerative disease called fragile X-associated tremor/ataxia syndrome (FXTAS) and Fragile X-associated primary ovarian insufficiency (FXPOI) in adulthood. In the last years an increasingly board spectrum of clinical manifestations including psychiatric disorders have been described as occurring at a greater frequency among <italic>FMR1</italic> premutation carriers. Herein, we reviewed the neuroimaging findings reported in relation with psychiatric symptomatology in adult <italic>FMR1</italic> premutation carriers. A structured electronic literature search was conducted on <italic>FMR1</italic> premutation and neuroimaging yielding a total of 3,229 articles examined. Of these, 7 articles were analyzed and are included in this review. The results showed that the main radiological findings among adult <italic>FMR1</italic> premutation carriers presenting neuropsychiatric disorders were found on the amygdala and hippocampus, being the functional abnormalities more consistent and the volumetric changes more inconsistent among studies. From a molecular perspective, CGG repeat size, <italic>FMR1</italic> mRNA and FMRP levels have been investigated in relation with the neuroimaging findings. Based on the published results, FMRP might play a key role in the pathophysiology of the psychiatric symptoms described among <italic>FMR1</italic> premutation carriers. However, additional studies including further probes of brain function and a broader scope of psychiatric symptom measurement are required in order to obtain a comprehensive landscape of the neuropsychiatric phenotype associated with the <italic>FMR1</italic> premutation.</p>