Genetic contributions to visuospatial cognition in Williams syndrome: insights from two contrasting partial deletion patients / H. BROADBENT in Journal of Neurodevelopmental Disorders, 6-1 (December 2014)  

Public ISBD [article]  inJournal of Neurodevelopmental Disorders > 6-1 (December 2014) . - p.18 Titre : Genetic contributions to visuospatial cognition in Williams syndrome: insights from two contrasting partial deletion patients Type de document : Texte imprimé et/ou numérique Auteurs : H. BROADBENT, Auteur ; E. K. FARRAN, Auteur ; E. CHIN, Auteur ; K. METCALFE, Auteur ; M. TASSABEHJI, Auteur ; P. TURNPENNY, Auteur ; F. SANSBURY, Auteur ; E. MEABURN, Auteur ; Annette KARMILOFF-SMITH, Auteur Article en page(s) : p.18 Langues : Anglais (eng) Mots-clés : Gtf2i  Gtf2ird1  Limk1  Navigation  Visuospatial cognition  Williams syndrome Index. décimale : PER Périodiques Résumé : BACKGROUND: Williams syndrome (WS) is a rare neurodevelopmental disorder arising from a hemizygotic deletion of approximately 27 genes on chromosome 7, at locus 7q11.23. WS is characterised by an uneven cognitive profile, with serious deficits in visuospatial tasks in comparison to relatively proficient performance in some other cognitive domains such as language and face processing. Individuals with partial genetic deletions within the WS critical region (WSCR) have provided insights into the contribution of specific genes to this complex phenotype. However, the combinatorial effects of different genes remain elusive. METHODS: WE REPORT ON VISUOSPATIAL COGNITION IN TWO INDIVIDUALS WITH CONTRASTING PARTIAL DELETIONS IN THE WSCR: one female (HR), aged 11 years 9 months, with haploinsufficiency for 24 of the WS genes (up to GTF2IRD1), and one male (JB), aged 14 years 2 months, with the three most telomeric genes within the WSCR deleted, or partially deleted. RESULTS: Our in-depth phenotyping of the visuospatial domain from table-top psychometric, and small- and large-scale experimental tasks reveal a profile in HR in line with typically developing controls, albeit with some atypical features. These data are contrasted with patient JB's atypical profile of strengths and weaknesses across the visuospatial domain, as well as with more substantial visuospatial deficits in individuals with the full WS deletion. CONCLUSIONS: Our findings point to the contribution of specific genes to spatial processing difficulties associated with WS, highlighting the multifaceted nature of spatial cognition and the divergent effects of genetic deletions within the WSCR on different components of visuospatial ability. The importance of general transcription factors at the telomeric end of the WSCR, and their combinatorial effects on the WS visuospatial phenotype are also discussed. En ligne : http://dx.doi.org/10.1186/1866-1955-6-18 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=346 [article] Genetic contributions to visuospatial cognition in Williams syndrome: insights from two contrasting partial deletion patients [Texte imprimé et/ou numérique] / H. BROADBENT, Auteur ; E. K. FARRAN, Auteur ; E. CHIN, Auteur ; K. METCALFE, Auteur ; M. TASSABEHJI, Auteur ; P. TURNPENNY, Auteur ; F. SANSBURY, Auteur ; E. MEABURN, Auteur ; Annette KARMILOFF-SMITH, Auteur . - p.18. Langues : Anglais (eng) in Journal of Neurodevelopmental Disorders > 6-1 (December 2014) . - p.18 Mots-clés : Gtf2i  Gtf2ird1  Limk1  Navigation  Visuospatial cognition  Williams syndrome Index. décimale : PER Périodiques Résumé : BACKGROUND: Williams syndrome (WS) is a rare neurodevelopmental disorder arising from a hemizygotic deletion of approximately 27 genes on chromosome 7, at locus 7q11.23. WS is characterised by an uneven cognitive profile, with serious deficits in visuospatial tasks in comparison to relatively proficient performance in some other cognitive domains such as language and face processing. Individuals with partial genetic deletions within the WS critical region (WSCR) have provided insights into the contribution of specific genes to this complex phenotype. However, the combinatorial effects of different genes remain elusive. METHODS: WE REPORT ON VISUOSPATIAL COGNITION IN TWO INDIVIDUALS WITH CONTRASTING PARTIAL DELETIONS IN THE WSCR: one female (HR), aged 11 years 9 months, with haploinsufficiency for 24 of the WS genes (up to GTF2IRD1), and one male (JB), aged 14 years 2 months, with the three most telomeric genes within the WSCR deleted, or partially deleted. RESULTS: Our in-depth phenotyping of the visuospatial domain from table-top psychometric, and small- and large-scale experimental tasks reveal a profile in HR in line with typically developing controls, albeit with some atypical features. These data are contrasted with patient JB's atypical profile of strengths and weaknesses across the visuospatial domain, as well as with more substantial visuospatial deficits in individuals with the full WS deletion. CONCLUSIONS: Our findings point to the contribution of specific genes to spatial processing difficulties associated with WS, highlighting the multifaceted nature of spatial cognition and the divergent effects of genetic deletions within the WSCR on different components of visuospatial ability. The importance of general transcription factors at the telomeric end of the WSCR, and their combinatorial effects on the WS visuospatial phenotype are also discussed. En ligne : http://dx.doi.org/10.1186/1866-1955-6-18 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=346

Route knowledge and configural knowledge in typical and atypical development: a comparison of sparse and rich environments / E. K. FARRAN in Journal of Neurodevelopmental Disorders, 7-1 (December 2015)  

Public ISBD [article]  inJournal of Neurodevelopmental Disorders > 7-1 (December 2015) . - p.37 Titre : Route knowledge and configural knowledge in typical and atypical development: a comparison of sparse and rich environments Type de document : Texte imprimé et/ou numérique Auteurs : E. K. FARRAN, Auteur ; H. R. PURSER, Auteur ; Y. COURBOIS, Auteur ; M. BALLE, Auteur ; P. SOCKEEL, Auteur ; D. MELLIER, Auteur ; Mark BLADES, Auteur Article en page(s) : p.37 Langues : Anglais (eng) Mots-clés : Development  Down syndrome  Navigation  Spatial cognition  Williams syndrome Index. décimale : PER Périodiques Résumé : BACKGROUND: Individuals with Down syndrome (DS) and individuals with Williams syndrome (WS) have poor navigation skills, which impact their potential to become independent. Two aspects of navigation were investigated in these groups, using virtual environments (VE): route knowledge (the ability to learn the way from A to B by following a fixed sequence of turns) and configural knowledge (knowledge of the spatial relationships between places within an environment). METHODS: Typically developing (TD) children aged 5 to 11 years (N = 93), individuals with DS (N = 29) and individuals with WS (N = 20) were presented with a sparse and a rich VE grid maze. Within each maze, participants were asked to learn a route from A to B and a route from A to C before being asked to find a novel shortcut from B to C. RESULTS: Performance was broadly similar across sparse and rich mazes. The majority of participants were able to learn novel routes, with poorest performance in the DS group, but the ability to find a shortcut, our measure of configural knowledge, was limited for all three groups. That is, 59 % TD participants successfully found a shortcut, compared to 10 % participants with DS and 35 % participants with WS. Differences in the underlying mechanisms associated with route knowledge and configural knowledge and in the developmental trajectories of performance across groups were observed. Only the TD participants walked a shorter distance in the last shortcut trial compared to the first, indicative of increased configural knowledge across trials. The DS group often used an alternative strategy to get from B to C, summing the two taught routes together. CONCLUSIONS: Our findings demonstrate impaired configural knowledge in DS and in WS, with the strongest deficit in DS. This suggests that these groups rely on a rigid route knowledge based method for navigating and as a result are likely to get lost easily. Route knowledge was also impaired in both DS and WS groups and was related to different underlying processes across all three groups. These are discussed with reference to limitations in attention and/or visuo-spatial processing in the atypical groups. En ligne : http://dx.doi.org/10.1186/s11689-015-9133-6 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=348 [article] Route knowledge and configural knowledge in typical and atypical development: a comparison of sparse and rich environments [Texte imprimé et/ou numérique] / E. K. FARRAN, Auteur ; H. R. PURSER, Auteur ; Y. COURBOIS, Auteur ; M. BALLE, Auteur ; P. SOCKEEL, Auteur ; D. MELLIER, Auteur ; Mark BLADES, Auteur . - p.37. Langues : Anglais (eng) in Journal of Neurodevelopmental Disorders > 7-1 (December 2015) . - p.37 Mots-clés : Development  Down syndrome  Navigation  Spatial cognition  Williams syndrome Index. décimale : PER Périodiques Résumé : BACKGROUND: Individuals with Down syndrome (DS) and individuals with Williams syndrome (WS) have poor navigation skills, which impact their potential to become independent. Two aspects of navigation were investigated in these groups, using virtual environments (VE): route knowledge (the ability to learn the way from A to B by following a fixed sequence of turns) and configural knowledge (knowledge of the spatial relationships between places within an environment). METHODS: Typically developing (TD) children aged 5 to 11 years (N = 93), individuals with DS (N = 29) and individuals with WS (N = 20) were presented with a sparse and a rich VE grid maze. Within each maze, participants were asked to learn a route from A to B and a route from A to C before being asked to find a novel shortcut from B to C. RESULTS: Performance was broadly similar across sparse and rich mazes. The majority of participants were able to learn novel routes, with poorest performance in the DS group, but the ability to find a shortcut, our measure of configural knowledge, was limited for all three groups. That is, 59 % TD participants successfully found a shortcut, compared to 10 % participants with DS and 35 % participants with WS. Differences in the underlying mechanisms associated with route knowledge and configural knowledge and in the developmental trajectories of performance across groups were observed. Only the TD participants walked a shorter distance in the last shortcut trial compared to the first, indicative of increased configural knowledge across trials. The DS group often used an alternative strategy to get from B to C, summing the two taught routes together. CONCLUSIONS: Our findings demonstrate impaired configural knowledge in DS and in WS, with the strongest deficit in DS. This suggests that these groups rely on a rigid route knowledge based method for navigating and as a result are likely to get lost easily. Route knowledge was also impaired in both DS and WS groups and was related to different underlying processes across all three groups. These are discussed with reference to limitations in attention and/or visuo-spatial processing in the atypical groups. En ligne : http://dx.doi.org/10.1186/s11689-015-9133-6 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=348

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