We are excited to share journal publications like this one resulting from FORWARD data. There are many more papers currently in development, and the future for Fragile X syndrome research is bright as more data is gathered.

The Future of Fragile X Syndrome: CDC Stakeholder Meeting Summary

Fragile X syndrome (FXS) is the most common known inherited cause of intellectual disability (ID). Males and females with FXS exhibit a wide range of intellectual ability and may experience various degrees of emotional, behavioral, sensory, learning, and social difficulties. In 1991, the gene responsible for FXS was identified on the X chromosome at q27.3 and named fragile x mental retardation 1 ( FMR1 ) gene.1 FXS and fragile X–associated disorders (FXD) are caused by a trinucleotide repeat (CGG) expansion mutation in the promoter region (exon 1) of FMR1 . Affected individuals with the full FXS mutation have >200 repeats. When the full mutation is present, FMR1 methylation occurs during gestation, which causes silencing of gene transcription.2 This in turn leads to a reduction or absence of fragile X mental retardation protein (FMRP), which is needed for brain development and function. Most males with FXS have ID. A small number of males have less impaired function due to methylation patterns or mosaicism. In females, FMRP levels depend on the X activation ratio, or the percent of cells expressing the normal allele on the active X chromosome,3 resulting in a range of normal intellectual ability to moderate ID. Over the past 2 decades, scientists have made significant advancements in identifying and describing genetic, molecular, and cellular underpinnings of FXS, allowing for a more precise diagnosis of this condition.


Riley C, Mailick M, Berry-Kravis E, Bolen J. The Future of Fragile X Syndrome: CDC Stakeholder Meeting Summary. Pediatrics. 2017;139 (Suppl 3):S147‐S152. doi:10.1542/peds.2016-1159B

Woman in protective glasses looking forward and upAbout the FORWARD Registry & Database

FORWARD is made possible by all the participating families sharing their life experiences for research. By giving families, doctors, scientific researchers, and policymakers an inside look into how Fragile X syndrome presents itself across the human lifespan, you’re involvement is a huge contribution toward more positive health outcomes and better care and services for future generations.

Below are more journal publications resulting from FORWARD data. 

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Mosaicism in Males with Fragile X Syndrome

By |Dec 28, 2021|

FORWARD // Participants with methylation mosaicism tended to have less severe intellectual disability and better social and functional skills. Knowing more about how FXS differs in people with and without methylation mosaicism may eventually help guide expectations and treatment of individuals with FXS.