Key Points
• Source: Frontiers in Neurology
• Conclusion: “Carriers of Fragile X premutation may have associated medical comorbidities, such as Fragile X-associated tremor and ataxia (FXTAS) and Fragile X-associated premature ovarian insufficiency (FXPOI) …. Specific learning and attention difficulties and resulting daily function difficulties correlate with an increased number of CGG repeats and are more likely to be associated as a common feature of premutation and full mutation in a female premutation carrier. Despite evidence of learning and attention difficulties, it is encouraging that most female carriers of the premutation and full mutation function well in most areas. Nevertheless, they face significant difficulties in specific areas of functioning such as driving, and confusion in times and schedules. Those daily function skills are mostly impacted by dyscalculia, right and left disorientation, and attention difficulties. This may aid to design specific interventions to address specific learning deficits in order to improve daily function skills and quality of life.”
• Israeli researchers examined the Fragile X premutation effect on cognition. They assumed that the continuous spectrum of specific learning and attention deficits directly correlated with the number of CGG repeats on the FMR1 gene. They included 108 women: 79 women harbored a premutation of 56-199 repeats on the FMR1 gene, and 19 women harbored a full mutation of more than 200 CGG repeats on FMR1 gene.
• Specific daily function skills (e.g., driving, writing checks) and learning difficulties correlated with the number of CGG repeats. Women with the full mutation were more likely diagnosed with ADHD or other learning disabilities.
• One limitation of the current study is that the researchers mostly used self-report questionnaires. Another limitation is that the genetic and epigenetic mechanisms are more complicated than merely the number of CGG repetitions. For example, the investigators didn’t examine X inactivation.