The psychological well-being of mothers raising a child with a developmental disability varies with the nature of the disability. Most research, however, has been focused on Down syndrome and autism. We added mothers whose adolescent or young adult son or daughter has fragile X syndrome. The sample was comprised of mothers of a child with fragile X syndrome (n 22), Down syndrome (n 39), or autism (n 174). Mothers of individuals with fragile X syndrome displayed lower levels of well-being than those of individuals with Down syndrome, but higher levels than mothers of individuals with autism, although group differences varied somewhat across different dimensions of well-being. The most consistent predictor of maternal outcomes was the adolescent or young adult's behavioral symptoms.

Researchers of mathematics learning disability (MLD) commonly use cutoff scores to determine which participants have MLD. Some researchers apply more restrictive cutoffs than others (e.g., performance below the 10th vs. below the 35th percentile). Different cutoffs may lead to groups of children that differ in their profile of math and related skills, including reading, visual-spatial, and working memory skills. The present study assesses the characteristics of children with MLD based on varying MLD definitions of math performance either below the 10th percentile (n = 22) or between the 11th and 25th percentile (n = 42) on the Test of Early Math Ability, second edition (TEMA-2). Initial starting levels and growth rates for math and related skills were examined in these two MLD groups relative to a comparison group (n = 146) whose TEMA-2 performance exceeded the 25th percentile. Between kindergarten and third grade, differences emerged in the starting level and growth rate, suggesting qualitative differences among the three groups. Despite some similarities, qualitative group differences were also observed in the profiles of math-related skills across groups. These results highlight differences in student characteristics based on the definition of MLD and illustrate the value of examining skill areas associated with math performance in addition to math performance itself.

Our findings support the notion that those with co-morbid FXS and autism represent a distinct subtype of FXS, with more impairment in receptive language and theory of mind even when controlling for their lower non-verbal IQ relative to those with only FXS. The greater cognitive impairments observed in those with co-morbid FXS and autism continues into adolescence and young adulthood; and the autism seen in those with FXS appears to be the same as idiopathic autism.

We investigated the receptive language of adolescents and young adults with Down syndrome (n = 25) or fragile X syndrome (n = 19). We were interested in syndrome differences and gender differences within fragile X. Comparison of the syndromes and MA-matched typically developing children (n = 24) revealed that individuals with the syndromes differed in relative achievements across the domains of receptive vocabulary, receptive syntax, and nonverbal cognition as well as in the organization of their linguistic knowledge. Comparison of males and females with fragile X revealed that each displayed synchronous development across the three domains, despite the fact that the receptive language levels of females surpassed that of males.