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PubMed2004

Locomotion skills in adults with cerebral palsy.

OBJECTIVES: To investigate self-reported locomotion skills in persons with cerebral palsy (CP) and to investigate variables potentially associated with deterioration of walking skills. DESIGN: Cross-sectional retrospective survey. SETTING AND SUBJECTS: A multidimensional mailed questionnaire was sent to 766 persons with CP, 18 years or over, without intellectual disabilities, living in Norway. MAIN OUTCOME MEASURES: The questionnaire consisted of demographic and diagnostic items, items on locomotion skills, and physical function (SF-36). RESULTS: In total 406 persons, 51% males and 49% females from 18 to 72 years (mean 34 years, SD 11 years) with all categories of CP responded. Median age for reported walking debut was 3 years, with a range from 1 to 14 years. In total 216 respondents (53%) walked without support, 104 persons (25%) walked with support, 39 persons (10%) had lost their walking skills, and 47 (12%) had never been able to walk. Mean level of physical function (SF-36) was 53 out of 100. There were 97 persons (27%) who reported improvement of walking skills, mainly before 25 years, 102 (28%) reported no change, and 160 (44%) reported deterioration, mainly before 35 years of age. Deterioration was significantly associated with older age, delayed walking debut and severe neurological impairment. Self-reported causes of deterioration were pain, fatigue and lack of adapted physical activity. CONCLUSION: Deterioration of locomotion skills is a significant problem in persons with CP from an early age, documenting the need for life-long follow-up. The predictors above should be investigated in further clinical studies, searching for potential causal pathways.

Adult↗

PubMed1998

Adults with Williams syndrome. Preliminary study of social, emotional and behavioural difficulties.

BACKGROUND: In recent years there has been an upsurge of interest in the study of distinctive patterns of behavioural and psychological characteristics associated with specific, biologically determined, intellectually disabling conditions. This study investigates whether such a profile can be identified in adults with Williams syndrome. METHOD: Parents and other care-givers were interviewed about the social, emotional and behavioural characteristics of 70 adults with Williams syndrome, aged 19 years to 39 years 9 months. RESULTS: The adults were reported to have high rates of behavioural and emotional difficulties, particularly in terms of poor social relationships, over-friendliness and social disinhibition, preoccupations and obsessions, and high levels of anxiety and distractibility. CONCLUSIONS: The findings provide preliminary support for the existence of a specific pattern of behavioural and personality characteristics and associated difficulties in adults with Williams syndrome, which persist from childhood and often require intervention from mental health professionals. Implications for clinical practice are considered.

Adolescent↗

PubMed1999

Clinical and imaging features of cortical malformations in childhood.

OBJECTIVE: To determine the types, relative frequencies, clinical features, and MRI characteristics of malformations of cortical development (MCD) occurring in a cohort of children referred to a tertiary pediatric center. METHODS: Original MR images were reviewed by two investigators, who were blinded to clinical details, to determine the elemental imaging features of each malformation and to label these malformations according to an existing system of classification. Clinical information was collected by a review of hospital records. RESULTS: A total of 109 children with MCD were identified. There were 58 boys and 51 girls, age 8 days to 18 years at initial imaging (mean age, 5 years). Seizures were present in 75%, developmental delay or intellectual disability in 68%, abnormal neurologic findings in 48%, and congenital anomalies apart from the CNS malformation in 18%. The main malformations identified were heterotopic gray matter (19%), cortical tubers (17%), focal cortical dysplasia (16%), polymicrogyria (16%), agyria/pachygyria (15%), schizencephaly/cleft (5%), transmantle dysplasia (5%), and hemimegalencephaly (4%). Eight patients had features of more than one malformation. Most lesions were multilobar (47%), with the frontal lobe being the most common lobe involved (78%). A total of 68% of patients had other cerebral malformations including ventricular dilatation or dysmorphism (46%) and abnormalities of the corpus callosum (29%). CONCLUSIONS: This study illustrates the spectrum of MCD in a pediatric cohort and highlights some of the differences between pediatric and adult patients. Patients with MCD presenting in childhood have a wider spectrum of malformations and more varied, often more severe, clinical manifestations. The lesions are frequently multifocal or generalized and many are associated with noncortical developmental brain anomalies.

Brain↗

PubMed2026

Fasudil induces anti-inflammatory transcriptomic changes and increased proliferation in human trisomy 21 neural progenitor cells.

Down syndrome (DS) results from trisomy for human chromosome 21 and is the most frequent genetic cause of intellectual disability. No effective treatments currently exist that improve neurodevelopment and cognition. Atypical brain development in individuals with DS is apparent before birth, which suggests that the optimal time to begin administration of therapies is prenatally. Human neural progenitor cell (NPC) cultures provide a tractable in vitro model system to examine the effects of trisomy 21 (T21) on neurodevelopment and to measure the effects of pharmacological interventions. Here, we report the results of preclinical studies evaluating 24 candidate therapies. RNA sequencing analyses found that euploid and T21 NPCs showed different transcriptomic responses to five candidate pharmacotherapies. The Rho-associated coiled-coil kinase inhibitor fasudil increased proliferation of T21 NPCs, reduced expression of inflammatory pathway genes in T21 NPCs, and reduced markers of inflammation in LPS-stimulated microglial model systems. These results demonstrate that fasudil can alter multiple T21-associated abnormalities in a beneficial manner, suggesting that fasudil warrants further study as a candidate prenatal pharmacotherapy for DS.

Down Syndrome↗

PubMed2000

A systematic review of effective cognitive-behavioural supervision.

OBJECTIVES: A systematic review was undertaken of studies that have assessed objectively the impact of supervision and consultancy. As well as gauging effectiveness, we examined the methodological rigour of these studies. METHOD: Twenty-eight empirical studies of the change processes occurring between participants within the educational pyramid, 'consultant-->supervisor', 'supervisor-->supervisee' and 'supervisee-->patient', were analysed. The inclusion criteria also required that supervision was analysed under field conditions and there were objective measures of learning outcomes. Each study was analysed by reference to an evaluation manual, with two independent raters obtaining satisfactory reliability. RESULTS: Studies meeting the above criteria came mainly from the intellectual disability specialty and included many studies using cognitive-behavioural methodologies. The studies included in this sample had more rigorous methodologies than those reviewed by Ellis, Ladany, Krengel, and Schult (1996). The findings of the review suggested that the pyramid approach benefited patients. Closely monitoring the supervisee, modelling competence, providing specific instructions, goal setting and providing contingent feedback on performance were the dominant methods of supervision and were associated with benefits to supervisees. CONCLUSION: Despite the large body of literature on supervision, there have been relatively few empirical investigations of the educational pyramid. This work identified a number of studies with good methodological rigour, although these too often failed to provide adequate background and assessment details regarding each of the members of the pyramid, particularly the consultant. The results of cognitive-behavioural supervision were found to be positive.

Cognitive Behavioral Therapy↗

PubMed2004

Early predictors of language in children with and without Down syndrome.

Predictors of productive and receptive language development in 39 children with intellectual disabilities (17 with Down syndrome) and their parents were identified. Children were in the prelinguistic or first stage of productive language acquisition (Brown, 1973). The Down syndrome and non-Down syndrome groups were matched on several variables, including IQ, CA, and vocabulary level. After controlling for initial language level, we attempted to identify unique early predictors of language measured 6 months later. Results indicate that Down syndrome negatively affected language development. Additionally, frequency of optimal parental responding predicted later productive language above and beyond etiology. Finally, canonical vocal communication and commenting predicted later productive language only in children without Down syndrome.

Child↗

PubMed2005

Emotion recognition by children with Down syndrome: investigation of specific impairments and error patterns.

The ability of children with Down syndrome to recognize expressions of emotion was compared to performance in typically developing and nonspecific intellectual disability groups matched on either MA or a performance-related measure. Our goal was to (a) resolve whether specific emotions present recognition difficulties; (b) investigate patterns of errors; and (c) explore the relationships among emotion-recognition ability and cognitive, linguistic, and adaptive behavior levels. Emotion-recognition ability in the Down syndrome group was significantly poorer than in the typically developing group overall, particularly for fearful expressions. Error patterns and relationships between task performance and assessment measures also differed across groups. Findings are consistent with a neurological explanation of specific deficits in sociocognitive functioning in children with Down syndrome.

Adolescent↗

PubMedDate not supplied

Parent-reported health-related quality of life in children with congenital hearing loss: a population study.

OBJECTIVE: To report 1) health-related quality of life (HRQoL) in 7- to 8-year-old children with congenital hearing loss and 2) effects of severity and age of diagnosis on parent-reported child HRQoL. METHODS SETTING: State of Victoria, Australia. DESIGN: Two population-based cohorts of 7- to 8-year-old children. PARTICIPANTS: Cohort 1 consisted of 83 children (51 boys) fitted with hearing aids or cochlear implants for congenital hearing loss by 4.5 years, born before universal newborn hearing screening, and without intellectual disability (the Children with Hearing Impairment in Victoria OUTCOME Study). Cohort 2 consisted of 895 children representative of the Victorian 7- to 8-year-old school population (the 1997 Health of Young Victorians Study). OUTCOME: The 28-item parent-proxy Child Health Questionnaire measure of HRQoL. RESULTS: Response rate for cohort 1 was 67%; 22% had mild, 33% had moderate, 17% had severe, and 29% had profound hearing loss; and the mean nonverbal IQ was 105.4 (SD = 16.5). Children with hearing loss scored significantly more poorly than the normative sample on 6 Child Health Questionnaire scales (Role/Social-Physical, Behavior, Mental Health, Parent Impact-Emotional, Parent Impact-Time, and Family Activities) and on the Psychosocial Summary Score. HRQoL was poorer with milder losses, accounting for 10% and 11% of variance in the Physical and Psychosocial Summary scores, respectively. Age at diagnosis did not contribute significantly to the Summary scores, but only 11 children were diagnosed <6 months of age. CONCLUSIONS: Parent-reported psychosocial well-being of 7- to 8-year-old children with hearing loss is poorer than that of their hearing peers. Future studies should determine whether HRQoL has improved after introduction of universal newborn hearing screening.

Child↗

PubMed2005

Primary ovarian failure and deletions of the long arm of chromosome 3.

A 14 year-old girl was found to have a deletion of the distal segment of chromosome 3 [46,XX,Del(3)(q28-29)]. The main features of this presentation were mild intellectual disability, facial dysmorphism, short stature, kypho-scoliosis, and primary ovarian failure, an association that has not been described before in association with chromosome 3 deletion. The phenotype and presentation are compared with those of previous case reports.

Adolescent↗

PubMed2004

Impact of a walking program in people with down syndrome.

The purpose of this study was to evaluate the efficacy of a pain-free treadmill walking program in intellectually disabled (ID) adults with arterial occlusive disease. Fourteen participants with mild ID participated in the walking program. Six patients showed stable intermittent claudication. A control (nontreadmill, n = 12) group consisted of 4 individuals with intermittent claudication. Noninvasive determinations of lower-limb hemodynamics included photoplethysmography and ankle-brachial pressure. Pain levels were measured according to a pain pathophysiology index. The treadmill program consisted of individually prescribed low-endurance walking at a 0% incline done at a comfortable speed 3 times per week. All participants completed the 15-week walking program and showed significant improvements (p < 0.05) in walking speed, distance, and duration. Pain levels were reduced in individuals suffering from intermittent claudication. Blood hemodynamic parameters also showed significant improvements. In conclusion, low-intensity treadmill walking significantly improved the functional capacities of adult individuals with mild ID with vascular occlusion and reduced pain levels.

Aged↗

PubMed2026

Genomic landscape of autism spectrum disorder in Brazil.

Genomic studies of autism spectrum disorder (ASD) have largely excluded admixed populations. To address this gap, we characterized the genomic landscape of ASD in Brazil by combining a systematic literature review with whole-exome sequencing analysis of 441 Brazilian individuals and their families. Our analysis revealed a conclusive molecular diagnosis in 13.1% of probands. The diagnostic yield was higher among individuals with clinical features, particularly comorbid signs of intellectual disability, hypotonia, and seizures, providing a basis for prioritizing genetic testing. The sample presented a diverse ancestry, with major European, African, and Native American contributions. Notably, more than half of the identified rare risk variants were located on non-European haplotypes. Both de novo and inherited variants contributed to ASD risk, and we reinforce NPAS3 as a candidate ASD risk gene. This study provides the first comprehensive genomic overview of ASD in a large Brazilian cohort, reinforcing the critical need to include diversely admixed populations in genomic research to expand the understanding of ASD architecture and improve diagnostic strategies in resource-limited settings.

Journal Article↗

PubMed1994

Preference for reinforcers under varying schedule arrangements: A behavioral economic analysis.

The field of behavioral economics combines concepts from economics and operant conditioning to examine the influence of schedules or price on preference for reinforcers. Three case studies are reported in which behavioral economic analyses were used to assess relative preference for reinforcers shown by people with intellectual disabilities when schedule requirements varied. The studies examined (a) preference for different reinforcers, (b) substitutability of reinforcers, and (c) changes in preference as a function of schedule requirements.

Journal Article↗

PubMed1995

Effect of response practice variables on learning spelling and sight vocabulary.

Four experiments were conducted to examine variables associated with response practice as an instructional technique for individuals with intellectual disabilities. In Experiment 1, the effect of the cover component in the "cover write" method was evaluated, as were the comparative effects of written versus oral practice of spelling words by rehabilitation clients. The results showed that the cover procedure generally did not enhance performance over and above that produced by practice alone, and written practice generally was not superior to oral practice. Experiment 2 demonstrated that less response practice (i.e., five times) was as effective as more practice (i.e., 10 and 15 times) for teaching spelling to adolescents with developmental disabilities. Experiments 3 and 4 also showed that even less response practice (i.e., one time) was as effective as more practice (five times), and irrelevant practice following errors was as effective as relevant practice for teaching spelling and sight vocabulary to adolescents with behavior disorders and developmental disabilities, respectively. The findings suggest that a parsimonious procedure of limited response practice and positive reinforcement may be effective for the tasks and populations studied.

Journal Article↗

PubMed2026

Decreased H3K79 acetylation and dysregulation of neurodevelopmental genes in fetal down syndrome.

BACKGROUND: Down syndrome (DS), the most prevalent chromosomal disorder caused by trisomy 21, manifests intellectual disability and cognitive dysfunction. Cumulative studies confirm epigenetic pathways including DNA methylation and non-coding RNAs drive DS pathological progression. Histone post-translational modifications (PTMs) are core epigenetic regulators of fetal brain development. However, genome-wide PTM alterations and their downstream functions in fetal DS brains remain poorly characterized, leaving a key gap in revealing epigenetic mechanisms underlying DS neurodevelopmental defects. To address this, we aimed to establish the first comprehensive landscape of histone PTMs in fetal DS cortex and investigate whether specific PTM changes contribute to aberrant neurodevelopmental gene expression. METHODS: Fetal cortexs from control and DS groups were subjected to global histone modification profiling via high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). We detected mono-, di-, and tri-methylation, acetylation, homocysteinylation and malonylation on all four core histones (H2A, H2B, H3, H4). Chromatin immunoprecipitation sequencing (ChIP-seq) was used to map genomic binding profiles of H3 lysine 79 acetylation (H3K79ac). Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to quantify mRNA levels of candidate neurodevelopmental genes. RESULTS: HPLC-MS/MS analysis identified 172 distinct histone PTMs in control fetal cortices and 168 PTMs in DS fetal cortical samples. Quantitative comparison of 22 quantifiable histone PTMs revealed that H3K79ac showed the most prominent reduction in DS samples, with a 34% decrease (P<0.05). Chromatin immunoprecipitation (ChIP)-seq verified specific H3K79ac occupancy at the genomic loci of three vital neurodevelopmental genes: TNFSF13B, NXPH1 and CAMK4. Correspondingly, qRT-PCR revealed aberrant transcription levels of these three genes in DS fetal cortices. CONCLUSIONS: This study establishes the first quantitative landscape of histone PTMs in in DS fetal cortical tissues. We demonstrate that depleted H3K79ac acts as a candidate epigenetic driver of DS neuropathology by disrupting the transcription of critical neurodevelopmental genes. This work reveals a novel epigenetic mechanism and a promising therapeutic target for DS-related neurodevelopmental disorders.

Down syndrome (DS)↗

PubMed2025

Scalable single-cell total RNA-seq reveals non-coding programs in immunity, infection, and brain development.

Non-coding RNAs represent a widespread and diverse layer of post-transcriptional regulation across cell types and states, yet much of their diversity remains uncharted at single-cell resolution. This gap stems from the limitations of widely used single-cell RNA-sequencing protocols, which focus on polyadenylated transcripts and miss many short or non-polyadenylated RNAs. Here, we adapted single-cell RNA-sequencing on the 10x Genomics platform to capture a broad complement of coding and non-coding RNAs-including miRNAs, tRNAs, lncRNAs, histone RNAs, and non-adenylated viral transcripts. This approach enabled the discovery of rich, dynamic non-coding RNA programs across immune cells, virally infected hepatocytes, and the developing human brain. In dengue virus-infected hepatocytes, we detect non-adenylated viral transcripts and distinguish active from transcriptionally quiescent infected states, each with distinct host regulatory signatures. In brain tissue, we identify biotype-specific, cell-type-restricted non-coding RNAs, including miRNAs whose expression anticorrelates with predicted targets, consistent with post-transcriptional regulatory relationships. We show that MIR137, one of the strongest GWAS loci associated with schizophrenia and intellectual disability, is expressed specifically in Cajal-Retzius cells, an early-born but transient population that guides subsequent cortical neuron migration. These findings demonstrate the importance of non-coding RNAs in defining cell identity and state, and show how expanded transcriptome coverage can reveal additional layers of gene control-now accessible through practical and scalable single-cell profiling.

Journal Article↗

PubMed2003

Psychiatric disorders in Prader-Willi syndrome: epidemiology and management.

Although people with intellectual disabilities are at increased risk for psychiatric disorders, the type and rate of these problems differ between those with different causes for their retardation. In this paper, we review behavioural and psychiatric problems in persons with Prader-Willi syndrome, a disorder caused by a paternally derived deletion at chromosome 15(q11-q13) in about 70% of affected patients, and by maternal uniparental disomy in the majority of the remaining patients. In addition to the syndrome's characteristic hyperphagia and food seeking, individuals with Prader-Willi syndrome also have increased risks of nonfood, compulsive behaviours. These include skin picking, which is highly prevalent, as well as more variable rates of hoarding, redoing and concerns with symmetry, exactness, cleanliness, ordering and arranging. Relative to others with mental retardation, persons with Prader-Willi syndrome are at a marked increased risk for developing full-blown, obsessive-compulsive disorder. In addition, many people with Prader-Willi syndrome show increased rates of tantrums, oppositionality and aggression. Recent findings suggest that they also have an increased risk of psychotic disorder or affective illness with a psychotic component, especially young adult patients and those with the maternal uniparental disomy as opposed to paternal deletion. Dietary approaches include a reduced-calorie diet and increased physical activity, as well as close supervision around food and keeping food locked away. To date, neither CNS stimulants nor anorectic agents have been effective in treating hyperphagia, in part because hyperphagia in Prader-Willi syndrome is attributed to decreased satiation as opposed to increased hunger. Treatment for compulsivity and maladaptive behaviours include: behavioural programming; a structured, predictable routine; extra help with transitions; family support; and pharmacotherapy. Although formal drug studies have yet to be conducted, SSRIs have been effective in reducing skin picking, compulsivity and aggressive episodes in some individuals with Prader-Willi syndrome. Atypical antipsychotics have also proven helpful in persons with psychotic features or extreme aggression and impulsivity. Largely on the basis of case studies, the risks and benefits of these and other drugs in Prader-Willi syndrome are reviewed. Drug trials that move beyond case studies and that assess the relative efficacy of behavioural treatments alone or in combination with pharmacotherapy are sorely needed.

Antipsychotic Agents↗

PubMed2001

The linguistic and cognitive profile of Down syndrome: evidence from a comparison with fragile X syndrome.

In this paper, we report on the results of our research, which is designed to address two broad questions about the cognitive and linguistic profile of Down syndrome: (1) Which domains of functioning are especially impaired in individuals with Down syndrome? and (2) Which aspects of the language and cognitive profile of Down syndrome are syndrome specific? To address these questions, we focused on three dimensions of the Down syndrome profile--receptive language, expressive language, and theory of mind--and made comparisons to individuals with fragile X syndrome, which is an X-linked form of intellectual disability. We identified Down syndrome impairments on all three dimensions that were substantially greater than those seen in nonverbal cognition and that were not shared by individuals with fragile X syndrome. Clinical implications of these findings are considered.

Cognition Disorders↗

PubMed2001

Implicit versus explicit memory function in children with Down and Williams syndrome.

The present study was aimed at evaluating implicit memory processes in participants with Williams syndrome and comparing them to children with Down syndrome and to mental-age matched typically developing children. For this purpose, tests of verbal and visuo-perceptual explicit memory, verbal and visual repetition priming as well as procedural learning tasks were administered to 12 participants with Williams syndrome, 14 with Down syndrome and 32 typically developing children. Participants with Williams syndrome showed a level of repetition priming similar to that of mental-age typically developing controls. In contrast, children with Williams syndrome showed a reduced learning rate in the two procedural tasks. As regards children with Down syndrome, we document comparable implicit memory abilities. In contrast, regarding explicit memory, typically developing children performed better than individuals with Down syndrome. This finding is relevant for our knowledge about the qualitative aspects of the anomalous cognitive development in individuals with intellectual disabilities and the neurobiological substrate underlying this development.

Child↗