Many males with FXS meet criteria for ASD. This study was designed to (1) describe ASD symptoms in adolescent and young adult males with FXS (n = 44) and (2) evaluate the contributions to ASD severity of cognitive, language, and psychiatric factors, as well as FMRP (the protein deficient in FXS). A few ASD symptoms on the ADOS-2 were universal in…

Although males with fragile X syndrome (FXS) are frequently described as demonstrating autism symptomatology, there is much debate regarding whether the behavioral symptoms representing the core domains of autism are the result of the same or different underlying neurological/psychological mechanisms. The present study used a cross-sectional…

This study examined whether language skills and nonverbal cognitive skills were associated with clinician-observed restricted and repetitive behaviors (RRBs) in a sample of 115 children with autism spectrum disorders (ASD) at ages 2 and 3. By age 3, RRBs were significantly negatively correlated with receptive and expressive language, as well as…

Duplications of 7q11.23, deleted in Williams-Beuren Syndrome, have been implicated in autism spectrum disorders (ASDs). A 1.5 Mb duplication was identified in one girl with severe expressive language deficits and anxiety among 1,142 ASD individuals screened for this duplication. Family-based association studies of Tag-SNPs in three genes ("STX1A,"…

Unstructured mother-toddler interactions were examined in 18-month-old high- and low-risk children subsequently diagnosed (n = 12) or not diagnosed (n = 21) with autism spectrum disorders (ASD) at 36 months. Differences in maternal sensitivity were not found as a function of emergent ASD status. A differential-susceptibility moderation model of…

The current study examined consistency between parental reports on early language development and behaviors in non-language domains and observer-coded videotapes of young children with and without autism spectrum disorder (ASD) and autistic regression. Data are reported on 56 children (84% male) with ASD (early onset or autistic regression) and 14…

The maladaptive behaviors, personality, and language skills of a male whose chromosome analysis showed evidence of mosaicism with karyotype 49,XXXXY and 48,XXXY are described. Research on severity of mental handicap with extra chromosomes, delayed speech development, and discrepancy between verbal and performance intelligence is examined. (JDD)