OBJECTIVE: An updated review of literature was conducted to characterize the clinical unmet needs and burden associated with Fragile X syndrome (FXS).
BACKGROUND: FXS is the most common inherited cause of intellectual disability, and is caused by a mutation in the X chromosome on the fragile X mental retardation 1 (FMR1) gene. The full gene mutation can cause significant intellectual disability, greatly reduce functional abilities, education achievement, and social-emotional skills.
DESIGN/METHODS: PubMed served as the primary database for the electronic literature search. Abstracts were reviewed based on predefined criteria between 2006-2016, focusing on epidemiology, genetics, natural history, caregiver burden, treatment, guidelines, resource utilization and costs.
RESULTS: The original search yielded 4,698 unique articles. Following a review, 530 were retained, and 244 were summarized and cited. A majority of individuals experience anxiety and behavioral issues, such as attention problems, hyperactivity, mood instability, aggression, and self-injurious behavior. A variety of symptom-specific medications are used; these medications are reported as only being somewhat effective. Direct costs vary depending on the type of insurance coverage, with approximate median annual costs in the United States of $2500 to $7500 per patient. Indirect costs to families include time off from work, turning down a promotion, or changing jobs to ensure better work hours. Family quality of life is affected, with reports of low levels of social support and higher parenting stress.
CONCLUSIONS: There is a large volume of literature describing the FXS phenotype and emerging evidence on economic and caregiver burden. Despite the availability of symptom-specific medications, there is no treatment available that targets the etiology of FXS. A better understanding of anxiety and the precursors to behavioral issues as well as development of targeted medications is needed. Finally, there is a need for more comprehensive understanding of the impact of FXS on the family unit.
