9 research outputs found

    De novo CCND2 mutations leading to stabilization of cyclin D2 cause megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome

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    Activating mutations in genes encoding phosphatidylinositol 3-kinase (PI3K)-AKT pathway components cause megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome (MPPH, OMIM 603387). Here we report that individuals with MPPH lacking upstream PI3K-AKT pathway mutations carry de novo mutations in CCND2 (encoding cyclin D2) that are clustered around a residue that can be phosphorylated by glycogen synthase kinase 3β (GSK-3β). Mutant CCND2 was resistant to proteasomal degradation in vitro compared to wild-type CCND2. The PI3K-AKT pathway modulates GSK-3β activity, and cells from individuals with PIK3CA, PIK3R2 or AKT3 mutations showed similar CCND2 accumulation. CCND2 was expressed at higher levels in brains of mouse embryos expressing activated AKT3. In utero electroporation of mutant CCND2 into embryonic mouse brains produced more proliferating transfected progenitors and a smaller fraction of progenitors exiting the cell cycle compared to cells electroporated with wild-type CCND2. These observations suggest that cyclin D2 stabilization, caused by CCND2 mutation or PI3K-AKT activation, is a unifying mechanism in PI3K-AKT–related megalencephaly syndromes

    Genome-wide sequencing and the clinical diagnosis of genetic disease: The CAUSES study

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    Genome-wide sequencing (GWS) is a standard of care for diagnosis of suspected genetic disorders, but the proportion of patients found to have pathogenic or likely pathogenic variants ranges from less than 30% to more than 60% in reported studies. It has been suggested that the diagnostic rate can be improved by interpreting genomic variants in the context of each affected individual's full clinical picture and by regular follow-up and reinterpretation of GWS laboratory results. Trio exome sequencing was performed in 415 families and trio genome sequencing in 85 families in the CAUSES study. The variants observed were interpreted by a multidisciplinary team including laboratory geneticists, bioinformaticians, clinical geneticists, genetic counselors, pediatric subspecialists, and the referring physician, and independently by a clinical laboratory using standard American College of Medical Genetics and Genomics (ACMG) criteria. Individuals were followed for an average of 5.1 years after testing, with clinical reassessment and reinterpretation of the GWS results as necessary. The multidisciplinary team established a diagnosis of genetic disease in 43.0% of the families at the time of initial GWS interpretation, and longitudinal follow-up and reinterpretation of GWS results produced new diagnoses in 17.2% of families whose initial GWS interpretation was uninformative or uncertain. Reinterpretation also resulted in rescinding a diagnosis in four families (1.9%). Of the families studied, 33.6% had ACMG pathogenic or likely pathogenic variants related to the clinical indication. Close collaboration among clinical geneticists, genetic counselors, laboratory geneticists, bioinformaticians, and individuals’ primary physicians, with ongoing follow-up, reanalysis, and reinterpretation over time, can improve the clinical value of GWS

    De Novo and Inherited Loss-of-Function Variants in TLK2 : Clinical and Genotype-Phenotype Evaluation of a Distinct Neurodevelopmental Disorder

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    Next-generation sequencing is a powerful tool for the discovery of genes related to neurodevelopmental disorders (NDDs). Here, we report the identification of a distinct syndrome due to de novo or inherited heterozygous mutations in Tousled-like kinase 2 (TLK2) in 38 unrelated individuals and two affected mothers, using whole-exome and whole-genome sequencing technologies, matchmaker databases, and international collaborations. Affected individuals had a consistent phenotype, characterized by mild-borderline neurodevelopmental delay (86%), behavioral disorders (68%), severe gastro-intestinal problems (63%), and facial dysmorphism including blepharophimosis (82%), telecanthus (74%), prominent nasal bridge (68%), broad nasal tip (66%), thin vermilion of the upper lip (62%), and upslanting palpebral fissures (55%). Analysis of cell lines from three affected individuals showed that mutations act through a loss-of-function mechanism in at least two case subjects. Genotype-phenotype analysis and comparison of computationally modeled faces showed that phenotypes of these and other individuals with loss-of-function variants significantly overlapped with phenotypes of individuals with other variant types (missense and C-terminal truncating). This suggests that haploinsufficiency of TLK2 is the most likely underlying disease mechanism, leading to a consistent neurodevelopmental phenotype. This work illustrates the power of international data sharing, by the identification of 40 individuals from 26 different centers in 7 different countries, allowing the identification, clinical delineation, and genotype-phenotype evaluation of a distinct NDD caused by mutations in TLK2

    The elite athlete´s mental recovery

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    Att vila fysiskt är för många en självklarhet, däremot pratas det sällan om den mentala återhämtningen. Båda är viktiga och har stor påverkan på prestation och hälsa. I den här studien är syftet att undersöka elitidrottares upplevelser och erfarenheter av mental återhämtning. För att ta reda på detta har vi genomfört kvalitativa intervjuer. På vilket sätt respondenterna får återhämtning, hur de påverkas av frånvaro av mental återhämtning och om dessa idrottare upplever ett samband mellan frånvaron av mental återhämtning och psykisk ohälsa presenteras i resultatet. När vi analyserade resultaten av intervjuerna gjorde vi innehållsanalyser. Vi kom fram till att samtliga får återhämtning genom att tänka på annat än idrotten och genom att utöva aktiviteter som är roliga. Vid frånvaro av mental återhämtning upplevde majoriteten en försämrad prestation och att hälsan påverkades negativt. Respondenterna beskrev ett samband mellan psykisk ohälsa och frånvaro av mental återhämtning. Det finns relativt lite forskning inom detta område, däremot stämde resultaten med tidigare forskning som idag finns tillgänglig.To many people, resting physically is a matter of course, however, mental recovery is rarely talked about. Both are important and have major impact on performance and health. In this study, the aim is to investigate athletes experiences of mental recovery. In order to find out, we have conducted qualitative interviews. In what way the respondents receive recovery, how they are affected by the absence of mental recovery and if these athletes experience a connection between the absence of mental recovery and mental illness is presented in the results. When we analyzed the results of the interviews, we used content analyses. We concluded that all respondents receive recovery by thinking about other things than sport and by doing activities that are fun. In the absence of mental recovery, the majority experienced a deterioration in performance and a negative impact on health. The respondents described a link between mental illness and the absence of mental recovery. There is limited research in this area, but the results were consistent with previous research available today
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