Suchergebnisse

Hundreds of penetrant risk loci have been identified across different neurodevelopmental disorders (NDDs), and these often involve rare (<1% frequency) copy number variations (CNVs), which can involve one or more genes. Monozygotic (MZ) twin pairs are long thought to share 100% of their genomic information. However, genetic differences in the form of postzygotic somatic variants have been reported recently both in typically developing (TD) and in clinically discordant MZ pairs. We sought to investigate the contribution of rare CNVs in 100 twin pairs enriched for NDD phenotypes with a particular focus on postzygotic CNVs in MZ pairs discordant for autism spectrum disorder (ASD) using the Illumina Infinium PsychArray. In our sample, no postzygotic de novo CNVs were found in 55 MZ twin pairs, including the 13 pairs discordant for ASD. We did detect a higher rate of CNVs overlapping genes involved in disorders of the nervous system, such as a rare deletion affecting HNRNPU, in MZ pairs discordant and concordant for ASD in comparison with TD pairs (p = .02). Our results are in concordance with earlier findings that postzygotic de novo CNV events are typically rare in genomic DNA derived from saliva or blood, and suggests that the discordance of NDDs in our sample of twins is not explained by discordant CNVs. Still, studies investigating postzygotic variation in MZ discordant twins using DNA from different tissues and single cells and higher resolution genomics are needed in the future.

Neurodevelopmental disorders affect a substantial minority of the general population. Their origins are still largely unknown, but a complex interplay of genetic and environmental factors causing disturbances of the central nervous system's maturation and a variety of higher cognitive skills is presumed. Only limited research of rather small sample size and narrow scope has been conducted in neurodevelopmental disorders using a twin-differences design. The Roots of Autism and ADHD Twin Study in Sweden (RATSS) is an ongoing project targeting monozygotic twins discordant for categorical or dimensional autistic and inattentive/hyperactive-impulsive phenotypes as well as other neurodevelopmental disorders, and typically developing twin controls. Included pairs are 9 years of age or older, and comprehensively assessed for psychopathology, medical history, neuropsychology, and dysmorphology, as well as structural, functional, and molecular brain imaging. Specimens are collected for induced pluripotent (iPS) and neuroepithelial stem cells, genetic, gut bacteria, protein-/monoamine, and electron microscopy analyses. RATSS's objective is to generate a launch pad for novel surveys to understand the complexity of genotype-environment-phenotype interactions in autism spectrum disorder and attention-deficit hyperactivity disorder (ADHD). By October 2013, RATSS had collected data from 55 twin pairs, among them 10 monozygotic pairs discordant for autism spectrum disorder, seven for ADHD, and four for other neurodevelopmental disorders. This article describes the design, recruitment, data collection, measures, collected pairs' characteristics, as well as ongoing and planned analyses in RATSS. Potential gains of the study comprise the identification of environmentally mediated biomarkers, the emergence of candidates for drug development, translational modeling, and new leads for prevention of incapacitating outcomes.

Pathogenic variants in MYH3 cause distal arthrogryposis type 2A and type 2B3 as well as contractures, pterygia and spondylocarpotarsal fusion syndromes types 1A and 1B. These disorders are ultra-rare and their natural course and phenotypic variability are not well described. In this study, we summarize the clinical features and genetic findings of 17 patients from 10 unrelated families with vertebral malformations caused by dominant or recessive pathogenic variants in MYH3. Twelve novel pathogenic variants in MYH3 (NM_002470.4) were identified: three of them were de novo or inherited in autosomal dominant way and nine were inherited in autosomal recessive way. The patients had vertebral segmentation anomalies accompanied with variable joint contractures, short stature and dysmorphic facial features. There was a significant phenotypic overlap between dominant and recessive MYH3-associated conditions regarding the degree of short stature as well as the number of vertebral fusions. All monoallelic variants caused significantly decreased SMAD3 phosphorylation, which is consistent with the previously proposed pathogenic mechanism of impaired canonical TGF-beta signaling. Most of the biallelic variants were predicted to be protein-truncating, while one missense variant c.4244T>G,p.(Leu1415Arg), which was inherited in an autosomal recessive way, was found to alter the phosphorylation level of p38, suggesting an inhibition of the non-canonical pathway of TGF-beta signaling. In conclusion, the identification of 12 novel pathogenic variants and overlapping phenotypes in 17 affected individuals from 10 unrelated families expands the mutation and phenotype spectrum of MYH3-associated skeletal disorders. We show that disturbances of canonical or non-canonical TGF-beta signaling pathways are involved in pathogenesis of MYH3-associated skeletal fusion (MASF) syndrome. ; Funding Agencies|National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [81930068, 81772299, 81822030, 82072391, 81972132, 81672123, 81972037, 81902178]; Beijing Natural Science FoundationBeijing Natural Science Foundation [JQ20032, 7191007]; CAMS Innovation Fund for Medical Sciences (CIFMS) [2021-I2M-1-051, 2021-I2M-1-052]; Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences [2019PT320025]; Tsinghua University-Peking Union Medical College Hospital Initiative Scientific Research Program; PUMC Youth Fund & the Fundamental Research Funds for the Central Universities [3332019021]; Swedish Research CouncilSwedish Research CouncilEuropean Commission [K2015-54X-22 736-01-4, 2015-02227, 2018-03046]; Swedish Governmental Agency for Innovation Systems (Vinnova)Vinnova [2014-01438]; Marianne and Marcus Wallenberg Foundation; IngaBritt och Arne Lundbergs forskningsstiftelse; Byggmastare Olle Engkvist Stiftelse; Promobilia; Nyckelfonden; Stiftelsen Frimurare Barnhuset i Stockholm; Region Stockholm; Karolinska Institutet, Stockholm, Sweden; orebro University, orebro, Sweden; Sallskapet Barnavard; Karolinska InstitutetKarolinska Institutet; Stiftelsen Sallsyntafonden; Stiftelsen Samariten; Stiftelsen Promobilia; Region Stockholm [20180131, 20200500]; US National Institutes of Health (NIH), National Institute of Neurological Disorders and Stroke [NINDS R35 NS105078]; National Human Genome Research Institute/National Heart, Lung, and Blood Institute [NHGRI/NHLBI UM1 HG006542]; US NIH National Human Genome Research Institute [NHGRI K08 HG008986]