Infant head growth in male siblings of children with and without autism spectrum disorders

Departments of Psychiatry and Pediatrics, Washington University, Saint. Louis, Missouri.
Journal of Neurodevelopmental Disorders (Impact Factor: 3.27). 03/2010; 2(1):39-46. DOI: 10.1007/s11689-009-9036-5
Source: PubMed


PURPOSE: Previous research has indicated that children with autism exhibit accelerated head growth (HG) in infancy, although the timing of acceleration varies between studies. We examined infant HG trajectory as a candidate autism endophenotype by studying sibling pairs. METHODS: We retrospectively obtained serial head orbitofrontal circumference measurements of: a) 48 sibling pairs in which one (n=28) or both (n=20) sibs were affected by an autism spectrum disorder (ASD); and b) 85 control male sibling pairs. RESULTS: Rate of HG of ASD subjects was slightly accelerated compared to controls, but the magnitude of difference was below the limit of reliability of standard measurement methods. Sibling intra class correlation for rate of HG was highly statistically significant; the magnitude was significantly stronger among autism-affected families (ICC=.63) than among controls (ICC=.26), p<.01. CONCLUSION: Infant HG trajectory appears familial-possibly endophenotypic-but was not a reliable marker of autism risk among siblings of ASD probands in this sample.

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    • "ements and overall growth measurements must be recorded and controlled for before comparing head size between groups of children . Additional factors such as diet , activity levels , and medication side effects , ideally should also be taken into account . The use of control groups not representative of the general population is also problematic ( Constantino et al . , 2010a ; Mraz et al . , 2009 ; Raznahan et al . , 2013 ; Zwaigenbaum et al . , 2014 ) . When compared with CDC norms , local control groups of TD children differ quite dramatically in HC , weight , and stature , suggesting that either the TD samples were not representative of the population , or that the CDC norms currently being used are outd"
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    ABSTRACT: Head circumference growth in individuals with an Autism Spectrum Disorder (ASD) has been well characterized in the first two to three years of life and reflects a period of acceleration followed by a period of deceleration when compared with their typically developing (TD) peers. While this altered growth trajectory has been consistently found for head circumference, it is less clear if an abnormal growth trajectory also exists across measures of height and weight. Moreover, most studies have focused on infancy and early childhood, and no longitudinal data have been collected in older children with ASD. This review focuses on the physical growth trajectory of individuals with ASD, and proposes that a general growth dysregulation is present in ASD, and that an endophenotype within ASD may exist that is characteristic of extreme overgrowth. Two possible explanations for a general growth dysregulation are suggested: (1) a connective tissue disorder, which is frequently associated with increased height and disproportionate body ratios; and (2) a dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis, which regulates growth hormones. The existence of a general growth dysregulation, and possible endophenotype, may serve as a potential biological marker in ASD.
    Full-text · Article · Feb 2015 · Developmental Review
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    • "Though it is currently debated (Raznahan et al., 2013), ASD has been assumed for long to be a condition characterized by an early altered brain growth (see Courchesne et al., 2005, for a review; see Constantino et al., 2010; Hazlett et al., 2005, for large retrospective works). At birth, the head circumference of ASD individuals has been found to be slightly reduced (Courchesne et al., 2003) or of normal size (Hazlett et al., 2005). "
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    ABSTRACT: Current evidence suggests the phenotype of Autism Spectrum Disorder to be driven by a complex interaction of genetic and environmental factors impacting onto brain maturation, synaptic function and cortical networks. However, findings are heterogeneous and the exact neurobiological pathways of Autism Spectrum Disorder still remain poorly understood. The co-twin control or twin-differences design is a potentially powerful tool to disentangle causal genetic and environmental contributions on neurodevelopment in Autism Spectrum Disorder. To this end, monozygotic twins discordant for this condition provide unique means for the maximum control of potentially confounding factors. Unfortunately, only few studies of a rather narrow scope, and limited sample size, have been conducted. In an attempt to highlight the great potential of combining the brain connectome approach with monozygotic twins design, we first give an overview of the existing neurobiological evidence for Autism Spectrum Disorder and its cognitive correlates. Then, a special focus is made onto the brain imaging findings reported within populations of monozygotic twins phenotypically discordant for Autism Spectrum Disorder. Finally, we introduce the brain connectome model and describe an ongoing project using this approach among the largest cohort of monozygotic twins discordant for Autism Spectrum Disorder ever recruited.
    Full-text · Article · Apr 2014 · Autism
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    • "Head circumference (HC) is a widely used proxy of neural growth and brain size in paediatric and research settings [1]. HC, as the occipital-frontal perimeter of the head, is related to individual differences in neuroanatomy [2]. "
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    ABSTRACT: The measurement of head circumference (HC) is widely used in clinical and research settings as a proxy of neural growth. Although it could aid data collection, no studies have explored either the reliability of adult self-measurements or parental measurements of young children. This study therefore aimed to examine whether adult self and parental measurement of HC constitute reliable data. A total of 57 adults (32 male) were asked to measure their HC twice following written instructions (adult self-measurement). These measures were compared to those of a researcher independently measuring the same participant's HC twice. Additionally, mothers of 25 children (17 male) were also asked to measure their child's HC (parental measure), and again this was compared to researcher measurements of the child's HC. The intraclass correlation coefficient between adult self- and researcher measurement was 0.84 and between parent and researcher measurement was 0.99. The technical error of measurement was also acceptable, within the range of a skilled anthropometrist. The high degree of agreement between researcher and adult self-measurement/parental measurement of HC demonstrates that these different assessors produce similarly reliable and reproducible data. This suggests adult self- and parental measurements can reliably be used for data collection to enable valid large-scale developmental and clinical studies of HC.
    Full-text · Article · Jan 2014 · Molecular Autism
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