Objectives: Fragile-X premutation carriers have been considered asymptomatic patients for a long time. It has been, however, demonstrated that the premutation is also involved in clinical pathology, such as premature ovarian failure, the fragile-X-associated tremor/ataxia syndrome, and a distinct neurocognitive and behavioral phenotype, which includes psychiatric problems. To define better this neuropsychiatric phenotype associated with premutation carriers and to minimize a possible environmental effect, we examined psychiatric and depressive symptoms in 34 FMR1 premutation carrier mothers of children with fragile-X syndrome in comparison with two control groups (39 mothers with a non-fragile-X syndrome mentally retarded child and 39 mothers from the general population).
Methods: All participants completed both questionnaires, which assess psychiatric symptoms (the symptom checklist-90-revised) and depression (Beck Depression Inventory).
Results: Both groups of mothers with a mentally retarded child showed greater susceptibility to psychological problems than the control group without a mentally retarded child, but FMR1 premutated mothers evidenced a higher tendency to depression. These results suggest that, despite the stress of caring for a child with mental retardation, the premutation by itself could be responsible for some psychiatric traits.
Conclusion: Our findings reinforce the hypothesis of a pathogenic gene-brain-behavior mechanism in the premutation range.