The power of parenting and a Fragile X
A gene on a “fragile” site of the X chromosome is the most common cause of inherited developmental disability and the leading genetic cause of autism. Fragile X Syndrome impacts not just individuals but families through generations. A mutation in the FMR1 gene occurring in one individual can result in descendants who are increasingly affected. A segment on the gene called a CGG triplet lengthens from the normal 5 to 40 repeats to more than 200 in people with full mutation FXS. Then the gene shuts down and prevents the production of a protein crucial to neural development. But even those with fewer repeats—both males and female carriers—are at risk for disorders later in life.
This is the background of one of the most important studies of this population to date. University Distinguished Professor Steven Warren and Associate Professor Nancy Brady, were awarded a ve-year, $2.4 million grant from the Eunice Kennedy Shriver National Institute of Child Health and Human Development to continue their 10-year longitudinal study of the effect of parenting on 55 children with FXS, now adolescents, and their mothers.
“Because this is one of the longest studies ever on individuals with FXS, we can ask fundamental questions about the relationships between environment and development over time,” Warren said.
Those questions include how parenting behaviors, measured across early and middle childhood, in uence the adolescents’ developmental trajectories and how these trajectories vary based on child gender, autism status and molecular measures of genetics.
Mothers are of particular interest in this study because female carriers of the mutation in the FMR1 gene often start showing some symptoms of the disorder such as anxiety and depression in their 40s and 50s when their children become adolescents.
The study will also examine the extent to which the parenting that the researchers observed in early and middle childhood predicts differences in adolescent behavior and development. The researchers saw the powerful effects of parenting on early vocabulary acquisition for which they found evidence even years later, as well as on cognition and adaptive behaviors.
“There is a lot of research on the biology of FXS, but much less on the environment’s effect over time,” Warren said. “Parents are usually a daily constant in their child’s lives, and their interactions have both short-term and cumulative effects on their children’s development and behavior. Consequently, they represent a nearly ideal environmental measure.”