MAP1B mutations cause intellectual disability and extensive white matter deficit

Publisher's version (útgefin grein). Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.Discovery of coding variants in genes that confer risk of neurodevelopmental disorders is an important step towards understanding the pathophysiology of these disorders. Wholegenome sequencing of 31,463 Icelanders uncovers a frameshift variant (E712KfsTer10) in microtubule-associated protein 1B (MAP1B) that associates with ID/low IQ in a large pedigree (genome-wide corrected P = 0.022). Additional stop-gain variants in MAP1B (E1032Ter and R1664Ter) validate the association with ID and IQ. Carriers have 24% less white matter (WM) volume (β = −2.1SD, P = 5.1 × 10−8), 47% less corpus callosum (CC) volume (β = −2.4SD, P = 5.5 × 10−10) and lower brain-wide fractional anisotropy (P = 6.7 × 10−4). In summary, we show that loss of MAP1B function affects general cognitive ability through a profound, brain-wide WM deficit with likely disordered or compromised axons.We are grateful to the participants and we thank the psychologists, nurses and staff, in particular Berglind Eiriksdottir, at the Research Recruitment Center and technicians and staff at Röntgen Domus. We also thank the staff at deCODE genetics core facilities and all our colleagues for their important contribution to this work. L.J. received support from the Swedish Society of Medicine, the Swedish Brain Foundation and Swedish Society for Medical Research. The research leading to these results has received support from the Innovative Medicines Initiative Joint Undertaking under grant agreements’ no. 115008 (NEWMEDS) and no. 115300 (EUAIMS) of which resources are composed of EFPIA in-kind contribution and financial contribution from the European Union’s Seventh Framework Programme (EU-FP7/2007-2013), EU-FP7 funded grant no. 602450 (IMAGEMEND) and EU funded FP7-People-2011-IAPP grant agreement no. 286213 (PsychDPC).Peer Reviewe

Long-term outcome of children with autism who received different forms of early intervention during their preschool years: a pilot study of 15 young adults

Background: Studies on early intervention have reported significant gains for many children with autism. Knowledge on how these children fare in adulthood is limited. Objective: To examine long-term outcome of children with autism who received different forms of early intervention. Method: Participants were 15 young people who had all been diagnosed with ICD-10 childhood autism during the preschool years. Five received intervention based on the UCLA model for early intensive behavioral intervention, and 10 received eclectic treatment. Participants were followed from their first autism diagnosis during the preschool years (time 1) to the age of six years (time 2). The participants are now in their twenties (time 3), and at this point in time, information on autism symptoms, co-occurring disorders, quality of life, functioning, participation, adaptive behavior, and overall outcome was gathered from parents. Six of the participants answered questionnaires on quality of life, functioning, and participation. Results: The groups were comparable on all measures at time 1. Reassessment at time 2 showed that the early intensive behavioral intervention group had made significant gains in IQ, and that autism symptoms had decreased significantly, whereas such changes were not found for the eclectic treatment group. At time 3, most participants had considerable autism symptoms. Approximately half of them had received diagnosis of a co-occurring condition. Their quality of life and adaptive behavior was less favorable than that of the general population, but only a third had “poor” overall outcome. However, at time 3, hardly any differences were found between the groups. Conclusions: To maintain gains made during the preschool years, appropriate intervention and services may need to be extended into adulthood. These services should take into account the perceived needs of the individual, as expressed by himself/herself and his/her family.The work of S.L.J. on data collection at time 1 and time 2 was partly supported by the Icelandic Centre for Research 960810098.Peer Reviewe

Interrogating the Genetic Determinants of Tourette’s Syndrome and Other Tic Disorders Through Genome-Wide Association Studies

OBJECTIVE:: Tourette's syndrome is polygenic and highly heritable. Genome-wide association study (GWAS) approaches are useful for interrogating the genetic architecture and determinants of Tourette's syndrome and other tic disorders. The authors conducted a GWAS meta-analysis and probed aggregated Tourette's syndrome polygenic risk to test whether Tourette's and related tic disorders have an underlying shared genetic etiology and whether Tourette's polygenic risk scores correlate with worst-ever tic severity and may represent a potential predictor of disease severity. METHODS:: GWAS meta-analysis, gene-based association, and genetic enrichment analyses were conducted in 4,819 Tourette's syndrome case subjects and 9,488 control subjects. Replication of top loci was conducted in an independent population-based sample (706 case subjects, 6,068 control subjects). Relationships between Tourette's polygenic risk scores (PRSs), other tic disorders, ascertainment, and tic severity were examined. RESULTS:: GWAS and gene-based analyses identified one genome-wide significant locus within FLT3 on chromosome 13, rs2504235, although this association was not replicated in the population-based sample. Genetic variants spanning evolutionarily conserved regions significantly explained 92.4% of Tourette's syndrome heritability. Tourette's-associated genes were significantly preferentially expressed in dorsolateral prefrontal cortex. Tourette's PRS significantly predicted both Tourette's syndrome and tic spectrum disorders status in the population-based sample. Tourette's PRS also significantly correlated with worst-ever tic severity and was higher in case subjects with a family history of tics than in simplex case subjects. CONCLUSIONS:: Modulation of gene expression through noncoding variants, particularly within cortico-striatal circuits, is implicated as a fundamental mechanism in Tourette's syndrome pathogenesis. At a genetic level, tic disorders represent a continuous spectrum of disease, supporting the unification of Tourette's syndrome and other tic disorders in future diagnostic schemata. Tourette's PRSs derived from sufficiently large samples may be useful in the future for predicting conversion of transient tics to chronic tic disorders, as well as tic persistence and lifetime tic severity