Pubmed du 27/02/12

Pubmed du jour

2012-02-27 12:03:50

1. Brown KF, Long SJ, Ramsay M, Hudson MJ, Green J, Vincent CA, Kroll JS, Fraser G, Sevdalis N. {{UK parents’ decision-making about measles-mumps-rubella (MMR) vaccine 10 years after the MMR-autism controversy: A qualitative analysis}}. {Vaccine};2012 (Feb 27);30(10):1855-1864.

BACKGROUND AND OBJECTIVES: Public concern about an unsubstantiated link between MMR vaccine and autism stemmed from a 1998 paper by Dr Andrew Wakefield and colleagues, and the substantial media coverage which that work attracted. Though the Wakefield paper is now discredited and an MMR-autism link has never been demonstrated empirically, this concern has manifested in over a decade of suboptimal MMR uptake. Few qualitative studies have explored parents’ MMR decision-making since uptake began to improve in 2004. This study updates and adds methodological rigour to the evidence base. METHODS: 24 mothers planning to accept, postpone or decline the first MMR dose (MMR1) for their 11-36 month-old children, described their decision-making in semi-structured interviews. Mothers were recruited via General Practice, parents’ groups/online forums, and chain referral. MMR1 status was obtained from General Practice records 6 months post-interview. Interview transcripts were coded and interpreted using a modified Grounded Theory approach. RESULTS: Five themes were identified: MMR vaccine and controversy; Social and personal consequences of MMR decision; Health professionals and policy; Severity and prevalence of measles, mumps and rubella infections; Information about MMR and alternatives. Results indicated that MMR1 acceptors were sympathetic toward Wakefield as a person, but universally rejected his study which sparked the controversy; parents opting for single vaccines expressed the sense that immune overload is not a consideration but that not all three components of MMR are warranted by disease severity; and MMR1 rejectors openly criticised other parents’ MMR decisions and decision-making. CONCLUSIONS: This study corroborated some previous qualitative work but indicated that the shrinking group of parents now rejecting MMR comprises mainly those with more extreme and complex anti-immunisation views, whilst parents opting for single vaccines may use second-hand information about the controversy. In response, policymakers and practitioners should revise their expectations of today’s MMR decision-makers, and their methods for supporting them.

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2. Qiao Y, Tyson C, Hrynchak M, Lopez-Rangel E, Hildebrand J, Martell S, Fawcett C, Kasmara L, Calli K, Harvard C, Liu X, Holden JJ, Lewis ME, Rajcan-Separovic E. {{Clinical application of 2.7M Cytogenetics array for CNV detection in subjects with idiopathic autism and/or intellectual disability}}. {Clin Genet};2012 (Feb 27)

Higher resolution whole genome arrays facilitate the identification of smaller CNVs and their integral genes contributing to autism and/or intellectual disability (ASD/ID). Our study describes the use of one of the highest resolution arrays, the Affymetrix((R)) Cytogenetics 2.7M array, coupled with Quantitative Multiplex PCR of Short fluorescent Fragments (QMPSF) for detection and validation of small CNVs. We studied 82 subjects with ASD and ID in total (30 in the validation and 52 in the application cohort) and detected putatively pathogenic CNVs in 6/52 cases from the application cohort. This included a 130 Kb maternal duplication spanning exons 64-79 of the DMD gene which was found in a 3-year old boy manifesting autism and mild neuromotor delays. Other pathogenic CNVs involved 4p14, 12q24.31, 14q32.31, 15q13.2-13.3, and 17p13.3. We established the optimal experimental conditions which, when applied to select small CNVs for QMPSF confirmation, reduced the false positive rate from 60 to 25%. Our work suggests that selection of small CNVs based on the function of integral genes, followed by review of array experimental parameters resulting in highest confirmation rate using multiplex PCR, may enhance the usefulness of higher resolution platforms for ASD and ID gene discovery.

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3. Till SM, Wijetunge LS, Seidel VG, Harlow E, Wright AK, Bagni C, Contractor A, Gillingwater TH, Kind PC. {{Altered maturation of the primary somatosensory cortex in a mouse model of fragile X syndrome}}. {Hum Mol Genet};2012 (Feb 27)

Fragile X syndrome (FXS) is the most common inherited form of intellectual disability and results from the loss of the fragile X mental retardation protein (FMRP). Many fragile X-related cognitive and behavioral features emerge during childhood and are associated with abnormal synaptic and cellular organization of the cerebral cortex. Identifying the roles of FMRP in cortical development will provide a basis for understanding the pathogenesis of the syndrome. However, how the loss of FMRP influences the developmental trajectory of cortical maturation remains unclear. We took advantage of the stereotyped and well-characterized development of the murine primary somatosensory cortex to examine cortical maturation during a time-window that corresponds to late embryonic and early postnatal development in the human. In the Fmr1 knockout mouse, we find a delay in somatosensory map formation, alterations in the morphology profile of dendrites and spines of layer 4 neurons and a decrease in the synaptic levels of proteins involved in glutamate receptor signaling at times corresponding to the highest levels of FMRP expression. In contrast, cortical arealization, synaptic density in layer 4 and early postnatal regulation of mRNAs encoding synaptic proteins are not altered in Fmr1 knockout mice. The specificity of the developmental delay in Fmr1 knockout mice indicates that the loss of FMRP does not result in a general stalling of cerebral cortex maturation. Instead, our results suggest that inaccurate timing of developmental processes caused by the loss of FMRP may lead to alterations in neural circuitry that underlie behavioral and cognitive dysfunctions associated with FXS.

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