There is increasing evidence that
neurodevelopmental differences in people with Fragile X syndrome (FraX) may be
explained by differences in glutamatergic metabolism. Pre-mutation carriers of FraX were originally
considered to be unaffected although several recent reports demonstrate
neuroanatomical, cognitive and emotional differences from controls. However there are few studies on brain
metabolism in premutation carriers of FraX.
used proton magnetic resonance spectroscopy
to compare neuronal integrity of a number of brain metabolites including
N-Acetyl Aspartate, Creatine + Phosphocreatinine, Choline, myoInositol and Glutamate containing substances (Glx) in
17 male premutation carriers of FraX and 16 male healthy control individuals.
There was no significant
between-group difference in the concentration of any measured brain
metabolites. However there was a
differential increase in N-acetyl aspartate with aging in premutation FraX individuals
compared to controls.
This is the first 1H-MRS
study to examine premutation FraX individuals. Although
we demonstrated no difference in the concentration of any of the metabolites
examined between the groups, this may be due to the large age ranges included
in the two samples. The
differential increase in NAA levels with aging which may reflect an abnormal synaptic pruning process.