Pubmed du 25/03/09

Pubmed du jour

2009-03-25 12:03:50

1. Bremer A, Giacobini M, Nordenskjold M, Brondum-Nielsen K, Mansouri M, Dahl N, Anderlid B, Schoumans J. {{Screening for copy number alterations in loci associated with autism spectrum disorders by two-color multiplex ligation-dependent probe amplification}}. {Am J Med Genet B Neuropsychiatr Genet};2009 (Mar 24)

The autism spectrum disorder (ASD) is a heterogenous condition characterized by impaired socialization and communication in association with stereotypic behaviors. ASD is highly heritable and heterogeneous with a complex genetic etiology. Recurrent submicroscopic deletions or duplications have been identified in a subgroup of individuals with ASD using array technology. Adequate genetic testing for these genomic imbalances have not yet been widely implemented in the diagnostic setting due to lack of feasible and cost-effective methods as well as difficulties to interpret the clinical significance of these small copy number variants (CNVs). We developed a multiplex ligation-dependent probe amplification (MLPA) assay to investigate its usefulness for detection of copy number alterations (CNAs) in autistic patients. This test proved to be easy to perform, fast, cost-effective, and suitable for reliable detection of multiple loci in a single reaction. We screened 148 autistic patients for 15 different loci covering 26 genes and found a 15q11-13 interstitial duplication that had escaped detection by conventional karyotyping in 1.3% of the patients. Synthetic probe MLPA allows for a flexible analysis of a continuously increasing number of CNAs associated with autism. Our result show that MLPA assay is an easy and cost-effective method for the identification of selected CNAs in diagnostic laboratories. (c) 2009 Wiley-Liss, Inc.

2. Shattuck PT, Durkin M, Maenner M, Newschaffer C, Mandell DS, Wiggins L, Lee LC, Rice C, Giarelli E, Kirby R, Baio J, Pinto-Martin J, Cuniff C. {{Timing of Identification Among Children With an Autism Spectrum Disorder: Findings From a Population-Based Surveillance Study}}. J{ Am Acad Child Adolesc Psychiatry};2009 (Mar 23)

OBJECTIVE:: At what age are children with an autism spectrum disorder (ASD) identified by community providers? What factors influence the timing of when children are identified with ASDs? This study examined the timing of when children with ASDs are identified. METHOD:: Data came from 13 sites participating in the Centers for Disease Control and Prevention’s 2002 multisite ongoing autism surveillance program, the Autism and Developmental Disabilities Monitoring Network. Survival analysis was used to examine factors that influence the timing of community-based identification and diagnosis. RESULT:: Data from health and education records reveal that the median age of identification was 5.7 years (SE 0.08 years). Parametric survival models revealed that several factors were associated with a younger age of identification: being male, having an IQ of 70 or lower, and having experienced developmental regression. Significant differences in the age of identification among the 13 sites were also discovered. CONCLUSIONS:: The large gap between the age at which children can be identified and when they actually are identified suggests a critical need for further research, innovation, and improvement in this area of clinical practice.

3. Thambirajah AA, Eubanks JH, Ausio J. {{MeCP2 post-translational regulation through PEST domains: two novel hypotheses: potential relevance and implications for Rett syndrome}}. {Bioessays};2009 (Mar 24)

Mutations in the methyl-CpG-binding protein 2 (MeCP2) cause Rett syndrome, a severe neurodevelopmental disease associated with ataxia and other post-natal symptoms similar to autism. Much research interest has focussed on the implications of MeCP2 in disease and neuron physiology. However, little or no attention has been paid to how MeCP2 turnover is regulated. The post-translational control of MeCP2 is of critical importance, especially as subtle increases or decreases in MeCP2 amounts can affect neuron morphology and function. The latter point is of particular importance for gene therapeutic approaches in which exogenous wild-type MeCP2 is being introduced into diseased neurons. Further to this, we propose two hypotheses. The first hypothesis discusses the poly-ubiquitin-mediated post-translational regulation of MeCP2 through its two PEST domains. The second hypothesis explores the use of histone deacetylase inhibitors to modulate the amounts of MeCP2 expressed in conjunction with the aforementioned therapeutic approaches.