Reading and phonological skills in boys with fragile X syndrome.

Although reading skills are critical for the success of individuals with intellectual disabilities, literacy has received little attention in fragile X syndrome (FXS). This study examined the literacy profile of FXS. Boys with FXS (n = 51; mean age 10.2 years) and mental age-matched boys with typical development (n = 35) participated in standardized assessments of reading and phonological skills. Phonological skills were impaired in FXS, while reading was on-par with that of controls. Phonological awareness predicted reading ability and ASD severity predicted poorer phonological abilities in FXS. Boys with FXS are capable of attaining reading skills that are commensurate with developmental level and phonological awareness skills may play a critical role in reading achievement in FXS.

Trajectories and predictors of the development of very young boys with fragile X syndrome.

OBJECTIVE: To describe the development of young boys with fragile X syndrome (FXS). METHODS: Fifty-five boys (aged 8-48 months at study entry) with the full mutation FXS received multiple developmental assessments. RESULTS: As expected, the boys' rate of development was significantly lower than chronological age expectations. No evidence of slowing in the rate of development was found. Autistic behavior was negatively associated with development, but maternal IQ was not. Developmental delays were evident in some domains as early as 9 months; however, initial detection of delays is complicated by measures and criteria used. Developmental age scores at 31 months of age were related to scores obtained at 61 months of age only in the global composite and visual reception domain. CONCLUSIONS: Developmental delays are evident in some infants with FXS as young as 9 months of age. Pediatric psychologists need to be informed about the developmental profiles in young children with FXS to accurately diagnose, treat, and support these children and their families.

Developmental trajectories and correlates of sensory processing in young boys with fragile X syndrome.

BACKGROUND AND PURPOSE: No longitudinal study on sensory processing in children with fragile X syndrome (FXS) exists. This study examined developmental trajectories and correlates of sensory processing from infancy through preschool years in 13 boys with FXS. METHOD: Participants were assessed using observational and parent-report measures 2-6 times between 9 and 54 months of age. RESULTS: Over time, an increasing proportion of boys displayed sensory processing that differed significantly from test norms. Observational measures were more sensitive than parent-reports early in infancy. Age and developmental quotient significantly predicted levels of hyporesponsiveness; there was a trend for hyperresponsiveness to increase with age. Baseline physiological and biological measures were not predictive. CONCLUSIONS: Sensory processing problems are observable early and grow increasingly problematic from infancy through the preschool ages. Early identification and intervention may attenuate long-term difficulties for children with FXS.

Executive functions in young males with fragile X syndrome in comparison to mental age-matched controls: baseline findings from a longitudinal study.

The performance of 54 boys with fragile X syndrome (FXS), ages 7 to 13 years, was compared to that of a group of typically developing boys who were matched on mental age (MA) and ethnicity across multiple measures of executive function (EF). Boys with FXS varied in their ability to complete EF measures, with only 25.9% being able to complete a set-shifting task and 94.4% being able to complete a memory for word span task. When compared to the control group, and controlling for MA and maternal education, boys with FXS showed significant deficits in inhibition, working memory, cognitive flexibility/set-shifting, and planning. No group differences were observed in processing speed. Mental age significantly impacted performance on working memory, set-shifting, planning, and processing speed tasks for both groups. In boys with FXS, MA significantly predicted performance on working memory and set-shifting tasks. Our findings suggest that deficits in EF in boys with FXS are not solely attributable to developmental delays but, rather, present as a true array of neurocognitive deficits.

Memory skills of boys with fragile X syndrome.

Multiple aspects of memory were examined in 42 boys with fragile X syndrome and a comparison group of 42 typically developing boys matched on MA. Working memory, incidental memory, and deliberate memory were assessed with a battery that included both free-recall and recognition tasks. Findings indicated that boys with fragile X syndrome performed more poorly than their matches on most measures. The exception was free recall, in which their accuracy was equal to that of the control participants. Results from analyses of a subset of boys with fragile X syndrome who exhibit characteristics of autism and their MA matches, though preliminary, support the conclusion that memory deficits are especially marked in boys who have fragile X syndrome and evidence autistic behaviors.

A comparison of oral structure and oral-motor function in young males with fragile X syndrome and Down syndrome.

This study compared the oral structure and oral-motor skills of 59 boys with fragile X syndrome (FXS), 34 boys with Down syndrome (DS), and 36 developmentally similar typically developing (TD) boys. An adaptation of the J. Robbins and T. Klee (1987) Oral Speech Motor Protocol was administered to participants and their scores on measures of oral structure and accuracy on speech motor and oral-motor tasks were analyzed. Boys with FXS scored lower than TD boys on oral structure, most oral function tasks, and all speech function tasks. Boys with DS scored lower than boys with FXS and TD boys on oral structure, and lower than TD boys on 1 oral function task and all speech function tasks. Boys with FXS and TD boys scored higher on speech function than oral function tasks, while boys with DS scored higher on oral function than speech function tasks. Boys with FXS and boys with DS repeated single syllable words with greater accuracy than multiple syllable words, while the TD boys produced both types of words with equal accuracy. These results suggest that boys with FXS and boys with DS exhibit atypical oral structure and motor function, yet differ in specific oral-motor patterns.

Autistic behavior in children with fragile X syndrome: prevalence, stability, and the impact of FMRP.

We examined autistic behavior in a cross-sectional sample of 179 children with fragile X syndrome (FXS) and a longitudinal subset of 116 children using the Childhood Autism Rating Scale (CARS) to (a) determine a prevalence of autistic behavior in FXS, (b) examine the stability of autistic ratings over time, and (c) assess the association between the fragile X mental retardation protein (FMRP) and autistic behavior. Approximately 21% of the sample of 129 children (25.9% of boys) scored at or above the cutoff for autism. CARS scores increased slowly, yet significantly, over time, and low levels of FMRP were associated with higher mean levels of autistic behavior as measured by the CARS.

Video analysis of sensory-motor features in infants with fragile X syndrome at 9-12 months of age.

This study utilized retrospective video analysis to distinguish sensory-motor patterns in infants with fragile X syndrome (FXS) (n = 11) from other infants [i.e., autism (n = 11), other developmental delay (n = 10), typical (n = 11)] at 9-12 months of age. Measures of development, autistic features, and FMRP were assessed at the time of entry into the study. Home videos collected from families were edited and coded with previously validated procedures. Findings revealed a pattern of sensory-motor features (e.g., repetitive leg movements, posturing, less sophistication/repetitive use of objects) associated with FXS, and suggest these infants were most similar to the group of infants with other developmental delays, irrespective of co-existing autistic symptoms later in life. Infant sensory-motor features in the FXS group were more predictive of an early developmental milestone (i.e., age walking) than later, more broad, developmental outcomes, or FMRP. Implications for early identification and differential diagnosis are discussed.

Mapping nonverbal IQ in young boys with fragile X syndrome.

This study examines the developmental changes in nonverbal intellectual functioning evident in males with fragile X syndrome (FXS) measured by the Leiter International Performance Scales-Revised (Leiter-R). The Leiter-R provides both IQ scores and associated growth scores which permit the examination of both age-based IQ scores and overall intellectual growth. Participants were 45 males with full mutation FXS and ranged in age from 4.0 to 13.8 years. Each child was assessed annually using the Leiter-R as part of a larger longitudinal battery for an average of 3.5 assessments per child and a range of 2-6 assessments, representing a total of 156 assessment occasions. Longitudinal analyzes of Leiter scores consisted primarily of hierarchical linear modeling, with the impact of chronological age, maternal education, fragile X mental retardation 1 protein (FMRP), autistic behaviors also being assessed. Findings revealed a significant linear decline in nonverbal IQ scores, with no effects of maternal education, autistic behaviors, or FMRP on mean level or rate of change in IQ scores over time. The decline slowed significantly around 8 years of age, but scores continued to decline into the 12th year of age. In contrast, a significant linear increase was observed in Leiter-R growth scores, which was negatively influenced by autistic behaviors. The rate of increase did not change over time, and neither mean level nor rate of increase was influenced by maternal education or FMRP levels. These findings suggest that declines in IQ are the result of steady, but suboptimal intellectual growth, rather than a true deterioration in overall intellectual functioning.

Developmental screening and detection of developmental delays in infants and toddlers with fragile X syndrome.

Three developmental screening tests (the Denver-II, Battelle Developmental Inventory Screening Test, and Early Language Milestone Scale-2) were administered to 18 infants and toddlers (13 boys and 5 girls) with confirmed diagnoses of fragile X syndrome as part of a comprehensive developmental assessment at 9, 12, and 18 months of age. The Denver-II identified delays for 10 of 11 boys at 9 months of age and the Denver-II and the Early Language Milestone Scale-2 identified delays in 100% of the boys at 12 and 18 months. The Battelle Developmental Inventory Screening Test identified delays in 75% of the children at 12 and 18 months. When compared with more comprehensive developmental tests (Mullen Scales of Early Learning and Receptive-Expressive Emergent Language Scale-2), the screening tests concurred at least 76% of the time at the 12- and 18-month assessments. These results indicate that developmental delays could be detected in most children with fragile X syndrome through routine developmental screening by the age of 9 to 12 months.

Adaptive behavior in children with fragile X syndrome.

Adaptive behavior over time in 70 children with fragile X syndrome, ages 1 to 12 years, was examined using the Vineland Adaptive Behavior Scales. With a mean of 4.4 assessments per child, adaptive behavior skills increased steadily and gradually over time. Children with less autistic behavior and higher percentages of FMPR expression showed better performance on all areas of adaptive behavior. Children without autistic behavior displayed higher scores and rates of growth on the Daily Living Skills domain, with the lowest scores in Socialization. Comparison to Brief IQs indicate that children with fragile X syndrome display nonverbal IQs superior to their adaptive behavior when they are below age 10 but that these skills seem to converge as they get older.

Early Intervention Practices and Communication Intervention Strategies for Young Males With Fragile X Syndrome.

PURPOSE: This study describes speech-language pathologists' impressions of the communication difficulties of young males with fragile X syndrome (FXS) and the need for both syndrome-specific and individualized interventions. The findings of a regional study that identified speech-language pathologists' impressions of the speech, language, and behavioral difficulties experienced by males with FXS and an array of interventions used by speech-language pathologists to improve communication skills for these children are reported. METHODS: Fifty-one speech-language pathologists providing intervention for males with FXS ranging in age from 2 to 9 years (mean age=6;3 [years;months]) were interviewed. RESULTS: The majority of the speech-language pathologists reported that boys with FXS exhibit a visually based, experiential or wholistic learning preference. They emphasized the necessity of making environmental accommodations for limited attention span, difficulties with topic and activity transitions, sensory deficits, and low threshold for anxiety. They reported that speech goals focused on slowing rate and increasing precision for verbal children and both low and high levels of assistive technology for nonverbal or minimally verbal children. Language goals focused on listening, auditory comprehension, and narrative/conversation skills. Pragmatic goals emphasized social dialogue, role playing, and topic maintenance. CLINICAL IMPLICATIONS: This study suggests that young males with FXS present the clinician with a constellation of behaviors and communication impairments that are both syndrome specific and symptom familiar. The specific communication strengths and deficits described by clinicians working with these children are common to many children with speech and language impairments compounded by cognitive deficits. Intervention programs for young boys with FXS should also attend closely to the specific behavioral (e.g., increased anxiety, attention deficits) and sensory "overload" problems they often exhibit before designing a tailored intervention program.