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Query: UMLS:C0004352 (autism)
 32,579 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Traditionally, autism and specific language impairment (SLI) are regarded as distinct disorders, with differential diagnosis hinging on two features. First, in SLI one sees isolated language impairments in the context of otherwise normal development, whereas in autism a triad of impairments is seen, affecting communication, social interaction and behavioural repertoire. Second, there are different communication problems in these two conditions. Children with SLI have particular difficulty with structural aspects of language (phonology and syntax). In contrast, abnormal use of language (pragmatics) is the most striking feature of autism. However, recently, this conventional view has been challenged on three counts. First, children with autism have structural language impairments similar to those in SLI. Second, some children have symptoms intermediate between autism and SLT. Third, there is a high rate of language impairments in relatives of people with autism, suggesting aetiological continuities between SLI and autism. One interpretation of these findings is to regard autism as 'SLI plus', i.e. to assume that the only factor differentiating the disorders is the presence of additional impairments in autism. It is suggested that a more plausible interpretation is to regard structural and pragmatic language impairments as correlated but separable consequences of common underlying risk factors.
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PMID:Autism and specific language impairment: categorical distinction or continuum? 1452 Nov 95

The pediatric otolaryngologist cares for children who have abnormal language as a primary or secondary deficiency. Five children, each with a different form of language disorder, are presented. These are children with specific language impairment (SLI) expressive, pervasive developmental delay (autism), expressive language delay associated with severe to profound hearing loss early in life, language delay secondary to a moderate to severe hearing loss diagnosed late and not cared for, and language delay secondary delay secondary to social deprivation and otitis media with effusion.
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PMID:Five children--vignettes of language disorders. 1466 83

Specific language impairment is a neurodevelopmental disorder characterized by impairments essentially restricted to the domain of language and language learning skills. This contrasts with autism, which is a pervasive developmental disorder defined by multiple impairments in language, social reciprocity, narrow interests and/or repetitive behaviors. Genetic linkage studies and family data suggest that the two disorders may have genetic components in common. Two samples, from Canada and the US, selected for specific language impairment were genotyped at loci where such common genes are likely to reside. Significant evidence for linkage was previously observed at chromosome 13q21 in our Canadian sample (HLOD 3.56) and was confirmed in our US sample (HLOD 2.61). Using the posterior probability of linkage (PPL) to combine evidence for linkage across the two samples yielded a PPL over 92%. Two additional loci on chromosome 2 and 7 showed weak evidence for linkage. However, a marker in the cystic fibrosis transmembrane conductance regulator (7q31) showed evidence for association to SLI, confirming results from another group (O'Brien et al. 2003). Our results indicate that using samples selected for components of the autism phenotype may be a useful adjunct to autism genetics.
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PMID:Examination of potential overlap in autism and language loci on chromosomes 2, 7, and 13 in two independent samples ascertained for specific language impairment. 1513 8

Language deficits are among the core impairments of autism. We previously reported asymmetry reversal of frontal language cortex in boys with autism. Specific language impairment (SLI) and autism share similar language deficits and may share genetic links. This study evaluated asymmetry of frontal language cortex in a new, independent sample of right-handed boys, including a new sample of boys with autism and a group of boys with SLI. The boys with autism were divided into those with language impairment (ALI) and those with normal language ability (ALN). Subjects (right-handed, aged 6.2-13.4 years) included 22 boys with autism (16 ALI and 6 ALN), 9 boys with a history of or present SLI, and 11 normal controls. MRI brain scans were segmented into grey and white matter; then the cerebral cortex was parcellated into 48 gyral-based divisions per hemisphere. Group differences in volumetric asymmetry were predicted a priori in language-related regions in inferior lateral frontal (Broca's area) and posterior superior temporal cortex. Language impaired boys with autism and SLI both had significant reversal of asymmetry in frontal language-related cortex; larger on the right side in both groups of language impaired boys and larger on the left in both unimpaired language groups, strengthening a phenotypic link between ALI and SLI. Thus, we replicated the observation of reversed asymmetry in frontal language cortex reported previously in an independent autism sample, and observed similar reversal in boys with SLI, further strengthening a phenotypic link between SLI and a subgroup of autism. Linguistically unimpaired boys with autism had similar asymmetry compared with the control group, suggesting that Broca's area asymmetry reversal is related more to language impairment than specifically to autism diagnosis.
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PMID:Language-association cortex asymmetry in autism and specific language impairment. 1556 33

Previous research has found that people with autism generate few novel responses in ideational fluency tasks, and it has been suggested this deficit is a specific correlate of stereotyped/repetitive behavior. We assessed generativity in children with pragmatic language impairment (PLI) who showed communicative abnormalities resembling those seen in autism. We compared four groups: high-functioning autism; PLI; specific language impairment; and control. Generativity was measured using two fluency tasks previously shown to be sensitive to autistic disorder. Correlational analysis revealed a significant relationship between the percentage of correct responses on the fluency tasks and measures of communicative abnormality. It is often assumed that pragmatic difficulties are caused by limitations of social cognition. This study suggests that difficulties in generating relevant ideas can be another cause of autistic-like communicative abnormalities.
Autism 2005 Feb
PMID:Executive functions in children with communication impairments, in relation to autistic symptomatology. 1: Generativity. 1561 60

Although impairment in executive functions has been described in autism, there has been debate as to whether response inhibition is specifically affected. We compared four groups: high-functioning autism; pragmatic language impairment; specific language impairment; and control. Inhibition was assessed using two subtests from the Test of Everyday Attention for Children, one requiring a verbal response and the other a non-verbal response. Although we found evidence of inhibitory deficits, these were neither specific to autism, nor linked to particular aspects of autistic symptomatology. Rather, they appeared to be associated with poor verbal skills and inattention. It is suggested that future studies need to control for structural language skills and attention deficit when evaluating cognitive deficits in autism. Reliance on control groups matched solely on vocabulary level or nonverbal mental age may obscure the important role played by language skills in executive functions.
Autism 2005 Feb
PMID:Executive functions in children with communication impairments, in relation to autistic symptomatology. 2: Response inhibition. 1561 61

Deficient rapid temporal processing may contribute to impaired language development by interfering with the processing of brief acoustic transitions crucial for speech perception. Using magnetoencephalography, evoked neural activity (M50, M100) to two 40 ms tones passively presented in rapid succession was recorded in 10 neurologically normal adults and 40 8-17-year-olds with autism, specific language impairment, Asperger syndrome or typical development. While 80% of study participants with intact language (Asperger syndrome, typical development, adults) showed identifiable responses to the second tone, which presented rapid temporal processing demands, 65% of study participants with impaired language (autism, specific language impairment) did not, despite having shown identifiable responses to the first tone. Rapid temporal processing impairments may be fundamentally associated with impairments in language rather than autism spectrum disorder.
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PMID:Magnetoencephalography identifies rapid temporal processing deficit in autism and language impairment. 1572 32

We analyzed the FOXP2 gene, which encodes a putative transcription factor containing a polyglutamine tract and a forkhead DNA-binding domain, for a possible causative mutation in autism. FOXP2 was reported to be mutated in patients with a severe speech and language disorder. FOXP2 was located on chromosome 7q31, which is one of the loci involved in autism. Autism and specific language impairment share some of their clinical phenotypes. In addition, FOXP2 was expressed abundantly in the brain. We screened all of the exons of FOXP2 for causative mutations in 53 Japanese autistic patients using denaturing high-performance liquid chromatography and direct sequencing. A delCAA in exon 5 causing one glutamine deletion in the first polyglutamine tract was detected in four patients and in 2 of 50 control individuals. The frequency of the TT allele with the G to T base change in intron 15 was significantly high in the autistic population. The other base changes included one silent base change (A569G) in exon 5 and three in introns. Our results may suggest a relationship between autism and the FOXP2 gene or a gene located nearby.
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PMID:Absence of causative mutations and presence of autism-related allele in FOXP2 in Japanese autistic patients. 1573 2

Genome investigations of autism, attention deficit hyperactivity disorder (ADHD), and dyslexia suggest possible genetic overlap. Atypical cerebral asymmetry (ACA), the absence of the left hemisphere dominance for language, may be a shared phenotype due to genes located in regions of overlap. A binomal test is used to evaluate whether linked regions overlap more than expected by chance for 15 genome-wide scans in autism, ADHD, and dyslexia. Significant evidence of linkage overlap (P = 10(-7)) is seen for autism, ADHD, and dyslexia for seven chromosomal regions (2p11-12, 5p13, 7q22-33, 9q33-34, 13q22, 16p13, and 17p11-q11). Linkage analysis of ACA and molecular markers for 270 sibling pairs with ADHD is conducted using the Haseman-Elston statistic. Linkage analysis supports ACA as a shared phenotype with risk genes located on 9q33-34 or 16p13 (P < 0.004). Further support stems from the overlap of these regions in schizophrenia, bipolar illness, specific language impairment (SLI), and handedness, all traits associated with ACA. Autism, ADHD, and dyslexia share regions of linkage overlap and ACA may be a shared phenotype for such genes similar to HLA in autoimmune disease. Because ACA is associated with certain aspects of creativity, such risk genes may also be enhancer genes for creativity.
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PMID:Toward localizing genes underlying cerebral asymmetry and mental health. 1580 84

The study of language knowledge guided by a purely biological perspective prioritizes the study of syntax. The essential process of syntax is recursion--the ability to generate an infinite array of expressions from a limited set of elements. Researchers working within the biological perspective argue that this ability is possible only because of an innately specified genetic makeup that is specific to human beings. Such a view of language knowledge may be fully justified in discussions on biolinguistics, and in evolutionary biology. However, it is grossly inadequate in understanding language-learning problems, particularly those experienced by children with neurodevelopmental disorders such as developmental dyslexia, Williams syndrome, specific language impairment and autism spectrum disorders. Specifically, syntax-centered definitions of language knowledge completely ignore certain crucial aspects of language learning and use, namely, that language is embedded in a social context; that the role of envrironmental triggering as a learning mechanism is grossly underestimated; that a considerable extent of visuo-spatial information accompanies speech in day-to-day communication; that the developmental process itself lies at the heart of knowledge acquisition; and that there is a tremendous variation in the orthographic systems associated with different languages. All these (socio-cultural) factors can influence the rate and quality of spoken and written language acquisition resulting in much variation in phenotypes associated with disorders known to have a genetic component. Delineation of such phenotypic variability requires inputs from varied disciplines such as neurobiology, neuropsychology, linguistics and communication disorders. In this paper, I discuss published research that questions cognitive modularity and emphasises the role of the environment for understanding linguistic capabilities of children with neuro-developmental disorders. The discussion pertains to two specific disorders, developmental dyslexia and Williams syndrome.
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PMID:Language cannot be reduced to biology: perspectives from neuro-developmental disorders affecting language learning. 1582 48


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