Novel MED12 variant in a multiplex Fragile X syndrome family: dual molecular etiology of two X-linked intellectual disabilities with autism in the same family.

Novel MED12 variant in a multiplex Fragile X syndrome family: dual molecular etiology of two X-linked intellectual disabilities with autism in the same family. Mol Biol Rep. 2019 May 16;: Authors: Lahbib S, Trabelsi M, Dallali H, Sakka R, Bourourou R, Kefi R, Mrad R, Abdelhak S, Gaddour N Abstract Studies of X-linked pedigrees were the first to identify genes implicated in intellectual disability (ID) and autism spectrum disorder (ASD). However, some pedigrees present a huge clinical variability between the affected members. This intrafamilial heterogeneity may be due to cooccurrence of two disorders. In the present study, we describe a multiplex X-linked pedigree in which three siblings have ID, ASD and dysmorphic features but with variable severity. Through Fragile X syndrome test, we identified the full FMR1 mutation in only two males. Whole exome sequencing allowed us to identify a novel hemizygous variant (p.Gln2080_Gln2083del) in MED12 gene in two males. So, the first patient has FXS, the second has both FMR1 and MED12 mutations while the third has only the MED12 variant. MED12 mutations are implicated in several forms of X-linked ID. Family segregation and genotype-phenotype-correlation were in favor of a cooccurrence of two forms of X-linked ID. Our work provides further evidence of the involvement of MED12 in XLID. Moreover, through these results, it is noteworthy to raise awareness that intrafamilial heterogeneity in FXS multiplex families coul...
Source: Molecular Biology Reports - Category: Molecular Biology Authors: Tags: Mol Biol Rep Source Type: research

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Abstract Estimates of the prevalence of speech and motor speech disorders in persons with complex neurodevelopmental disorders (CND) can inform research in the biobehavioural origins and treatment of CND. The goal of this research was to use measures and analytics in a diagnostic classification system to estimate the prevalence of speech and motor speech disorders in convenience samples of speakers with one of eight types of CND. Audio-recorded conversational speech samples from 346 participants with one of eight types of CND were obtained from a database of participants recruited for genetic and behavioural studi...
Source: Clinical Linguistics and Phonetics - Category: Speech-Language Pathology Authors: Tags: Clin Linguist Phon Source Type: research
Fragile X syndrome (FXS) is the leading monogenic cause of autism and intellectual disability. FXS is caused by loss of expression of fragile X mental retardation protein (FMRP), an RNA-binding protein that regulates translation of numerous mRNA targets, some of which are present at synapses. While protein synthesis deficits have...
Source: Proceedings of the National Academy of Sciences - Category: Science Authors: Tags: Biological Sciences Source Type: research
r C Abstract Identifying the early signs of developmental disability is important for ensuring timely diagnosis and early intervention. Day-care workers may be in a prime position to notice potential developmental deviations, but it is unclear if they can accurately recognize subtle early signs of atypical development. Sixty day-care workers examined home-videos of very young children with fragile X syndrome and typically developing children. Results indicated that most day-care workers can distinguish typical and atypical development in general and might therefore have an important role in early identification. S...
Source: Journal of Autism and Developmental Disorders - Category: Psychiatry Authors: Tags: J Autism Dev Disord Source Type: research
Fragile X Syndrome (FXS) is one of the most common monogenic forms of autism and intellectual disability. Preclinical studies in animal models have highlighted the potential of pharmaceutical intervention strategies for alleviating the symptoms of FXS. However, whether treatment strategies can be tailored to developmental time windows that define the emergence of particular phenotypes is unknown. Similarly, whether a brief, early intervention can have long-lasting beneficial effects, even after treatment cessation, is also unknown. To address these questions, we first examined the developmental profile for the acquisition ...
Source: Science Translational Medicine - Category: Biomedical Science Authors: Tags: Research Articles Source Type: research
Fragile X syndrome(FXS) is most common congenital hereditary disease of low intelligence after Down Syndrome. Its main pathogenic gene is Fragile X mental retardation 1 (FMR1) gene associated with intellectual disability, autism and Fragile X-related primary ovarian insufficiency (FXPOI) and Fragile X-associated tremor/ataxia syndrome (FXTAS). Fmr1 gene transcription leads to the absence of fragile X mental retardation protein (FMRP). How to relieve or cure disorders associated with FXS has also become a clinically disturbing problem. Previous studies have recently shown that Long noncoding RNAs (lncRNA) contribute to the ...
Source: Frontiers in Genetics - Category: Genetics & Stem Cells Source Type: research
Abstract Sensory processing abnormalities are consistently associated with autism, but the underlying mechanisms and treatment options are unclear. Fragile X Syndrome (FXS) is the leading known genetic cause of intellectual disabilities and autism. One debilitating symptom of FXS is hypersensitivity to sensory stimuli. Sensory hypersensitivity is seen in both humans with FXS and FXS mouse model, the Fmr1 knock out (Fmr1 KO) mouse. Abnormal sensorimotor gating may play a role in the hypersensitivity to sensory stimuli. Humans with FXS and Fmr1 KO mice show abnormalities in acoustic startle response (ASR) and prepul...
Source: Brain Research - Category: Neurology Authors: Tags: Brain Res Source Type: research
ConclusionMetformin may be a candidate drug for treatment of several types of symptoms in individuals with FXS.
Source: Molecular Genetics & Genomic Medicine - Category: Genetics & Stem Cells Authors: Tags: ORIGINAL ARTICLE Source Type: research
This study determined if completeFMR1 mRNA silencing from FM alleles and/or levels ofFMR1 mRNA (if present) in blood are associated with intellectual functioning and autism features in FXS.MethodsThe study cohort included 98 participants (70.4% male) with FXS (FM-only and PM/FM mosaic) aged 1 –43 years. A control group of 14 females were used to establish controlFMR1 mRNA reference range. Intellectual functioning and autism features were assessed using the Mullen Scales of Early Learning or an age-appropriate Wechsler Scale and the Autism Diagnostic Observation Schedule-2nd Edition (ADOS-2), respectively.FMR1 mR...
Source: Molecular Autism - Category: Molecular Biology Source Type: research
Albert Sanfeliu1, Karsten Hokamp2, Michael Gill1 and Daniela Tropea1,3*1Neuropsychiatric Genetics, Department of Psychiatry, School of Medicine, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland2Department of Genetics, School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland3Department of Psychiatry, School of Medicine, Trinity College Institute for Neuroscience, Trinity College Dublin, Dublin, IrelandRett syndrome is a rare neuropsychiatric disorder with a wide symptomatology including impaired communication and movement, cardio-respiratory abno...
Source: Frontiers in Psychiatry - Category: Psychiatry Source Type: research
In conclusion, we further advanced the molecular understanding of mitochondrial dysfunction in RTT. Intensified mitochondrial O2 consumption, increased mitochondrial ROS generation and disturbed redox balance in mitochondria and cytosol may represent a causal chain, which provokes dysregulated proteins, oxidative tissue damage, and contributes to neuronal network dysfunction in RTT. Introduction Rett syndrome (RTT) is a progressive neurodevelopmental disorder. It primarily affects females, who show the first obvious symptoms within 6–18 months after birth. Among the characteristics are a regression of mental ...
Source: Frontiers in Physiology - Category: Physiology Source Type: research
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