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Biomedical subjects

Joseph Piven

Publications and source records attributed to Joseph Piven.

17 recordsLinked to original sources

Systematic screening for subtelomeric anomalies in a clinical sample of autism.

High-resolution karyotyping detects cytogenetic anomalies in 5-10% of cases of autism. Karyotyping, however, may fail to detect abnormalities of chromosome subtelomeres, which are gene rich regions prone to anomalies. We assessed whether panels of FISH probes targeted for subtelomeres could detect abnormalities beyond those identified by karyotyping in 104 individuals with Pervasive Developmental Disorders (PDDs) drawn from a general clinical population. Four anomalies were detected by karyotyping, while no additional anomalies were detected by subtelomere FISH or by probes targeted for 15q11.2q13 or 22q11.2 in subgroups of our sample. We conclude that while karyotyping may be more broadly indicated for autism than previously supposed, subtelomere FISH appears less likely to be a useful screening tool for unselected PDD populations.

Asperger Syndrome↗

Abnormal use of facial information in high-functioning autism.

Altered visual exploration of faces likely contributes to social cognition deficits seen in autism. To investigate the relationship between face gaze and social cognition in autism, we measured both face gaze and how facial regions were actually used during emotion judgments from faces. Compared to IQ-matched healthy controls, nine high-functioning adults with autism failed to make use of information from the eye region of faces, instead relying primarily on information from the mouth. Face gaze accounted for the increased reliance on the mouth, and partially accounted for the deficit in using information from the eyes. These findings provide a novel quantitative assessment of how people with autism utilize information in faces when making social judgments.

Adult↗

Communicative competence in parents of children with autism and parents of children with specific language impairment.

While the primary language deficit in autism has been thought to be pragmatic, and in specific language impairment (SLI) structural, recent research suggests phenomenological and possibly genetic overlap between the two syndromes. To compare communicative competence in parents of children with autism, SLI, and down syndrome (DS), we used a modified pragmatic rating scale (PRS-M). Videotapes of conversational interviews with 47 autism, 47 SLI, and 21 DS parents were scored blind to group membership. Autism and SLI parents had significantly lower communication abilities than DS parents. Fifteen percent of the autism and SLI parents showed severe deficits. Our results suggest that impaired communication is part of the broader autism phenotype and a broader SLI phenotype, especially among male family members.

Adult↗

The broad autism phenotype questionnaire.

The broad autism phenotype (BAP) is a set of personality and language characteristics that reflect the phenotypic expression of the genetic liability to autism, in non-autistic relatives of autistic individuals. These characteristics are milder but qualitatively similar to the defining features of autism. A new instrument designed to measure the BAP in adults, the Broad Autism Phenotype Questionnaire (BAPQ), was administered to 86 parents of autistic individuals and 64 community control parents. Sensitivity and specificity of the BAPQ for detecting the BAP were high (>70%). Parents of children with autism had significantly higher scores on all three subscales: aloof personality, rigid personality, and pragmatic language. This instrument provides a valid and efficient measure for characterizing the BAP.

Autistic Disorder↗

Analysis of face gaze in autism using "Bubbles".

One of the components of abnormal social functioning in autism is an impaired ability to direct eye gaze onto other people's faces in social situations. Here, we investigated the relationship between gaze onto the eye and mouth regions of faces, and the visual information that was present within those regions. We used the "Bubbles" method to vary the facial information available on any given trial by revealing only small parts of the face, and measured the eye movements made as participants viewed these stimuli. Compared to ten IQ- and age-matched healthy controls, eight participants with autism showed less fixation specificity to the eyes and mouth, a greater tendency to saccade away from the eyes when information was present in those regions, and abnormal directionality of saccades. The findings provide novel detail to the abnormal way in which people with autism look at faces, an impairment that likely influences all subsequent face processing.

Adult↗

User-guided 3D active contour segmentation of anatomical structures: significantly improved efficiency and reliability.

Active contour segmentation and its robust implementation using level set methods are well-established theoretical approaches that have been studied thoroughly in the image analysis literature. Despite the existence of these powerful segmentation methods, the needs of clinical research continue to be fulfilled, to a large extent, using slice-by-slice manual tracing. To bridge the gap between methodological advances and clinical routine, we developed an open source application called ITK-SNAP, which is intended to make level set segmentation easily accessible to a wide range of users, including those with little or no mathematical expertise. This paper describes the methods and software engineering philosophy behind this new tool and provides the results of validation experiments performed in the context of an ongoing child autism neuroimaging study. The validation establishes SNAP intrarater and interrater reliability and overlap error statistics for the caudate nucleus and finds that SNAP is a highly reliable and efficient alternative to manual tracing. Analogous results for lateral ventricle segmentation are provided.

Brain↗

Reduced relationship to cortical white matter volume revealed by tractography-based segmentation of the corpus callosum in young children with developmental delay.

OBJECTIVE: The corpus callosum is the primary anatomical substrate for interhemispheric communication, which is important for a range of adaptive and cognitive behaviors in early development. Previous studies that have measured the corpus callosum in developmental populations have been limited by the use of rather arbitrary methods of subdividing the corpus callosum. The purpose of this study was to measure the corpus callosum in a clinical group of developmentally delayed children using a subdivision that more accurately reflected the anatomical properties of the corpus callosum. METHOD: The authors applied tractography to subdivide the corpus callosum into regions corresponding to the cortical regions to and from which its fibers travel in a clinical group of very young children with developmental delay, a precursor to general mental retardation, in comparison with typically developing children. RESULTS: The data demonstrate that the midsagittal area of the entire corpus callosum is reduced in children presenting with developmental delay, reflected in the smaller area of each of the fiber-based callosal subdivisions. In addition, while the area of each subdivision was strongly and significantly correlated with the corresponding cortical white matter volume in comparison subjects, this correlation was prominently absent in the developmentally delayed group. CONCLUSIONS: A fiber-based subdivision successfully separates lobar regions of the corpus callosum, and the areas of these regions distinguish a developmentally delayed clinical group from the comparison group. This distinction was evident both in the area measurements themselves and in their correlation to the white matter volumes of the corresponding cortical lobes.

Atrophy↗

Cortical gray and white brain tissue volume in adolescents and adults with autism.

BACKGROUND: A number of studies have found brain enlargement in autism, but there is disagreement as to whether this enlargement is limited to early development or continues into adulthood. In this study, cortical gray and white tissue volumes were examined in a sample of adolescents and adults with autism who had demonstrated total brain enlargement in a previous magnetic resonance imaging (MRI) study. METHODS: An automated tissue segmentation program was applied to structural MRI scans to obtain volumes of gray, white, and cerebrospinal fluid (CSF) tissue on a sample of adolescent and adult males ages 13-29 with autism (n = 23) and controls (n = 15). Regional differences for brain lobes and brain hemispheres were also examined. RESULTS: Significant enlargement in gray matter volume was found for the individuals with autism, with a disproportionate increase in left-sided gray matter volume. Lobe volume enlargements were detected for frontal and temporal, but not parietal or occipital lobes, in the subjects with autism. Age and nonverbal IQ effects on tissue volume were also observed. CONCLUSIONS: These findings give evidence for left-lateralized gray tissue enlargement in adolescents and adults with autism, and demonstrate a regional pattern of cortical lobe volumes underlying this effect.

Adolescent↗

Evaluation of the chromosome 2q37.3 gene CENTG2 as an autism susceptibility gene.

Autism is a highly heritable neurodevelopmental syndrome with a complex genetic etiology for which no disease genes have yet been definitively identified. We ascertained three subjects with autism spectrum disorders and chromosome 2q37.3 terminal deletions, and refined the deletion breakpoint regions using polymorphism mapping and fluorescence in situ hybridization (FISH) probes. We then genotyped polymorphic markers downstream from the breakpoint region in a sample of autism affected sibling pair families. Both the chromosomal breakpoints and linkage analyses focused our attention on the gene centaurin gamma-2 (CENTG2), an attractive candidate gene based also on its function and pattern of expression. We therefore assessed CENTG2 for its involvement in autism by (1) screening its exons for variants in 199 autistic and 160 non-autistic individuals, and (2) genotyping and assessing intra-genic polymorphisms for linkage and linkage disequilibrium (LD). The exon screen revealed a Ser --> Gly substitution in one proband, an Arg --> Gly substitution in another, and a number of additional variants unique to the autism families. No unique variants were found in the control subjects. The genotyping produced strong evidence for linkage from two intronic polymorphisms, with a maximum two-point HLOD value of 3.96 and a posterior probability of linkage (PPL) of 51%. These results were contradicted, however, by substantially weaker evidence for linkage from multi-point analyses and by no evidence of LD. We conclude, therefore, that 2q37.3 continues to be a region of interest for autism susceptibility, and that CENTG2 is an intriguing candidate gene that merits further scrutiny for its role in autism.

ADP-Ribosylation Factors↗

Moderate sedation for MRI in young children with autism.

UNLABELLED: Autism is a pervasive neurodevelopmental disorder. Because of the deficits associated with the condition, sedation of children with autism has been considered more challenging than sedation of other children. OBJECTIVE: To test this hypothesis, we compared children with autism against clinical controls to determine differences in requirements for moderate sedation for MRI. MATERIALS AND METHODS: Children ages 18-36 months with autism (group 1, n = 41) and children with no autistic behavior (group 2, n = 42) were sedated with a combination of pentobarbital and fentanyl per sedation service protocol. The sedation nurse was consistent for all patients, and all were sedated to achieve a Modified Ramsay Score of 4. Demographics and doses of sedatives were recorded and compared. RESULTS: There were no sedation failures in either group. Children in group 1 (autism) were significantly older than group 2 (32.02+/-3.6 months vs 28.16+/-6.7 months) and weighed significantly more (14.87+/-2.1 kg vs 13.42+/-2.2 kg). When compared on a per-kilogram basis, however, group 1 had a significantly lower fentanyl requirement than group 2 (1.25+/-0.55 mcg/kg vs 1.57+/-0.81 mcg/kg), but no significant difference was found in pentobarbital dosing between groups 1 and 2, respectively (4.92+/-0.92 mg/kg vs 5.21+/-1.6 mg/kg). CONCLUSION: Autistic children in this age range are not more difficult to sedate and do not require higher doses of sedative agents for noninvasive imaging studies.

Anesthetics, Intravenous↗

A case of autism and uniparental disomy of chromosome 1.

We report a male child with autism found to have maternal uniparental disomy (UPD) of chromosome 1. The child met diagnostic criteria for the three symptom domains of autism: language impairment, deficient social communication and excessively rigid and repetitive behaviours. He also had a variety of features often associated with autism, including mild mental retardation, small head circumference, hyperactivity, poor fine motor skills, slightly dysmorphic facial features and a heightened interest in olfactory stimulation. His brother, who did not have chromosome 1 UPD, was also autistic. The mother, but not the father, had a history of psychiatric illness and a number of personality and social traits similar to the core features of autism. The discovery of the cytogenetic abnormality was made during the course of a genome-wide linkage screen, wherein genotypes at 6 out of 17 chromosome 1 markers were non-Mendelian and all transmissions were consistent with UPD. Further genotyping (a total of 54 markers) revealed alternating regions of heterodisomy and isodisomy. Whereas chromosome 1 UPD has not been shown to cause disease by effects on imprinting, numerous reports exist of the abnormality unmasking recessive disease-causing mutations. In agreement with this, one of the regions of isodisomy overlaps an emerging chromosome 1 region of interest in autism located at 150-160 Mb.

Autistic Disorder↗

Magnetic resonance imaging and head circumference study of brain size in autism: birth through age 2 years.

CONTEXT: While the neuroanatomical basis of autism is not yet known, evidence suggests that brain enlargement may be characteristic of this disorder. Inferences about the timing of brain enlargement have recently come from studies of head circumference (HC). OBJECTIVES: To examine brain volume and HC in individuals with autism as compared with control individuals. DESIGN: A cross-sectional study of brain volume was conducted at the first time point in an ongoing longitudinal magnetic resonance imaging study of brain development in autism. Retrospective longitudinal HC measurements were gathered from medical records on a larger sample of individuals with autism and local control individuals. SETTING: Clinical research center. PARTICIPANTS: The magnetic resonance imaging study included 51 children with autism and 25 control children between 18 and 35 months of age (the latter included both developmentally delayed and typically developing children). Retrospective, longitudinal HC data were examined from birth to age 3 years in 113 children with autism and 189 local control children. MAIN OUTCOME MEASURES: Cerebral cortical (including cortical lobes) and cerebellar gray and white matter magnetic resonance imaging brain volumes as well as retrospective HC data from medical records were studied. RESULTS: Significant enlargement was detected in cerebral cortical volumes but not cerebellar volumes in individuals with autism. Enlargement was present in both white and gray matter, and it was generalized throughout the cerebral cortex. Head circumference appears normal at birth, with a significantly increased rate of HC growth appearing to begin around 12 months of age. CONCLUSIONS: Generalized enlargement of gray and white matter cerebral volumes, but not cerebellar volumes, are present at 2 years of age in autism. Indirect evidence suggests that this increased rate of brain growth in autism may have its onset postnatally in the latter part of the first year of life.

Age Factors↗

Preface.

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Animals↗

Evaluation of FOXP2 as an autism susceptibility gene.

A mutation in the gene FOXP2 was recently identified as being responsible for a complicated speech and language phenotype in a single large extended pedigree. This gene is of interest to autism because it lies in one of the most consistently linked autism chromosomal regions of interest. We therefore tested this gene for its involvement in autism in a large sample of autism families. We completely sequenced the exon containing the mutation, screened the remaining coding sequence using SSCP technology, and identified and genotyped two novel intronic tetranucleotide repeat polymorphisms that were then analyzed for evidence of linkage and linkage disequilibrium (LD). We identified two families in which heterozygous deletions of a small number of glutamines in a long poly-glutamine stretch were found in one parent and the autistic probands; no other non-conservative coding sequence changes were identified. Linkage and LD analyses were performed in 75 affected sibling pair families and in two subgroups of this sample defined by the presence/absence of severe language impairment. One allele appeared to have an opposite pattern of transmission in the language based subgroups, but otherwise the linkage and LD analyses were negative. We conclude that FOXP2 is unlikely to contribute significantly to autism susceptibility.

Alleles↗

Visual scanning of faces in autism.

The visual scanpaths of five high-functioning adult autistic males and five adult male controls were recorded using an infrared corneal reflection technique as they viewed photographs of human faces. Analyses of the scanpath data revealed marked differences in the scanpaths of the two groups. The autistic participants viewed nonfeature areas of the faces significantly more often and core feature areas of the faces (i.e., eyes, nose, and mouth) significantly less often than did control participants. Across both groups of participants, scanpaths generally did not differ as a function of the instructions given to the participants (i.e., "Please look at the faces in any manner you wish." vs. "Please identify the emotions portrayed in these faces."). Autistic participants showed a deficit in emotion recognition, but this effect was driven primarily by deficits in the recognition of fear. Collectively, these results indicate disorganized processing of face stimuli in autistic individuals and suggest a mechanism that may subserve the social information processing deficits that characterize autism spectrum disorders.

Adult↗

Structural and functional magnetic resonance imaging of autism.

Magnetic resonance imaging (MRI) of brain structures and function is uniquely suited to characterize the range of neuroanatomical and physiological changes that characterize the autism phenotype as it develops over time. In this review, we examine the scientific literature in MRI as applied to autism and related areas, over approximately the last decade, discussing findings which have emerged, methodological stumbling blocks which have been identified, and potential future directions. Structural MRI studies have recently begun to elucidate the neurodevelopmental underpinnings and brain-behavior relationships in autism while fMRI studies, building on the wealth of data in normal individuals, are beginning to characterize the underlying neuropsychological deficits of the disorder. Together, these two methods combine to contribute to a better understanding of the neural basis and brain phenotype of this disorder.

Autistic Disorder↗