Unaffected siblings of adolescents and adults with fragile X syndrome: Effects on maternal well-being.

The present study investigated the effects of children without disabilities on maternal physical and mental health in families with adolescents or adults with fragile X syndrome. Mothers with the FMR1 premutation ( N = 87) reported on behavior problems and functional limitations of their adolescent or adult child with fragile X syndrome and their own physical and mental health. Mothers also provided a blood sample to determine FMR1 CGG repeat length. The proportion of unaffected children in the family significantly buffered the effect of both child behavior problems and functional limitations on maternal self-rated health, such that having a higher proportion of unaffected children in the family had a protective effect on maternal health when the target child had more severe behavior problems and functional limitations. There was a similar buffering process for maternal depressive symptoms but at a trend level. Additionally, maternal CGG repeat length had a significant curvilinear association with self-rated health, indicating that mothers with midrange repeat lengths reported the poorest health, whereas mothers with lower and higher repeat lengths in the premutation range reported better health. The data suggest that unaffected children in the family may be an important resource for premutation carrier mothers. Findings are consistent with previous research indicating that mothers with varying levels of genetic liability have variable risk for health problems. (PsycINFO Database Record