Genetic modifiers of ambulation in the cooperative international Neuromuscular Research Group Duchenne natural history study

OBJECTIVE: We studied the effects of LTBP4 and SPP1 polymorphisms on age at loss of ambulation (LoA) in a multiethnic Duchenne muscular dystrophy (DMD) cohort. METHODS: We genotyped SPP1 rs28357094 and LTBP4 haplotype in 283 of 340 participants in the Cooperative International Neuromuscular Research Group Duchenne Natural History Study (CINRG-DNHS). Median ages at LoA were compared by Kaplan-Meier analysis and log-rank test. We controlled polymorphism analyses for concurrent effects of glucocorticoid corticosteroid (GC) treatment (time-varying Cox regression) and for population stratification (multidimensional scaling of genome-wide markers). RESULTS: Hispanic and South Asian participants (n=18, 41) lost ambulation 2.7 and 2 years earlier than Caucasian subjects (p=0.003, <0.001). The TG/GG genotype at SPP1 rs28357094 was associated to 1.2-year-earlier median LoA (p=0.048). This difference was greater (1.9 years, p=0.038) in GC-treated participants, whereas no difference was observed in untreated subjects. Cox regression confirmed a significant effect of SPP1 genotype in GC-treated participants (hazard ratio = 1.61, p=0.016). LTBP4 genotype showed a direction of association with age at LoA as previously reported, but it was not statistically significant. After controlling for population stratification, we confirmed a strong effect of LTBP4 genotype in Caucasians (2.4 years, p =0.024). Median age at LoA with the protective LTBP4 genotype in this cohort was 15.0 years, 16.0 for those who were treated with GC. INTERPRETATION: SPP1 rs28357094 acts as a pharmacodynamic biomarker of GC response, and LTBP4 haplotype modifies age at LoA in the CINRG-DNHS cohort. Adjustment for GC treatment and population stratification appears crucial in assessing genetic modifiers in DMDFil: Bello, Luca. Children's National Medical Center; Estados Unidos. Università di Padova; ItaliaFil: Kesari, Akanchha. Children's National Medical Center; Estados UnidosFil: Gordish Dressman, Heather. Children's National Medical Center; Estados UnidosFil: Cnaan, Avital. Children's National Medical Center; Estados Unidos. The George Washington University; Estados UnidosFil: Morgenroth, Lauren P.. Children's National Medical Center; Estados UnidosFil: Punetha, Jaya. Children's National Medical Center; Estados Unidos. The George Washington University; Estados UnidosFil: Duong, Tina. Children's National Medical Center; Estados UnidosFil: Henricson, Erik K.. University of California at Davis; Estados UnidosFil: Pegoraro, Elena. Università di Padova; ItaliaFil: McDonald, Craig M.. University of California at Davis; Estados UnidosFil: Hoffman, Eric P.. Children's National Medical Center; Estados Unidos. The George Washington University; Estados UnidosFil: Dubrovsky, Alberto. Cooperative International Neuromuscular Research Group Investigators; ArgentinaFil: Andreone, Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación en Biomedicina de Buenos Aires - Instituto Partner de la Sociedad Max Planck; Argentina. Cooperative International Neuromuscular Research Group Investigators; Argentina. Fundación Favaloro; ArgentinaFil: Cooperative International Neuromuscular Research Group Investigators. No especifica

Biallelic GRM7 variants cause epilepsy, microcephaly, and cerebral atrophy

Objective: Defects in ion channels and neurotransmitter receptors are implicated in developmental and epileptic encephalopathy (DEE). Metabotropic glutamate receptor 7 (mGluR7), encoded by GRM7, is a presynaptic G-protein-coupled glutamate receptor critical for synaptic transmission. We previously proposed GRM7 as a candidate disease gene in two families with neurodevelopmental disorders (NDDs). One additional family has been published since. Here, we describe three additional families with GRM7 biallelic variants and deeply characterize the associated clinical neurological and electrophysiological phenotype and molecular data in 11 affected individuals from six unrelated families. Methods: Exome sequencing and family-based rare variant analyses on a cohort of 220 consanguineous families with NDDs revealed three families with GRM7 biallelic variants; three additional families were identified through literature search and collaboration with a clinical molecular laboratory. Results: We compared the observed clinical features and variants of 11 affected individuals from the six unrelated families. Identified novel deleterious variants included two homozygous missense variants (c.2671G>A:p.Glu891Lys and c.1973G>A:p.Arg685Gln) and one homozygous stop-gain variant (c.1975C>T:p.Arg659Ter). Developmental delay, neonatal- or infantile-onset epilepsy, and microcephaly were universal. Three individuals had hypothalamic–pituitary–axis dysfunction without pituitary structural abnormality. Neuroimaging showed cerebral atrophy and hypomyelination in a majority of cases. Two siblings demonstrated progressive loss of myelination by 2 years in both and an acquired microcephaly pattern in one. Five individuals died in early or late childhood. Conclusion: Detailed clinical characterization of 11 individuals from six unrelated families demonstrates that rare biallelic GRM7 pathogenic variants can cause DEEs, microcephaly, hypomyelination, and cerebral atrophy. © 2020 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals, Inc on behalf of American Neurological Association

Mutations in GDP-mannose pyrophosphorylase b cause congenital and limb-girdle muscular dystrophies associated with hypoglycosylation of α-dystroglycan

Congenital muscular dystrophies with hypoglycosylation of α-dystroglycan (α-DG) are a heterogeneous group of disorders often associated with brain and eye defects in addition to muscular dystrophy. Causative variants in 14 genes thought to be involved in the glycosylation of α-DG have been identified thus far. Allelic mutations in these genes might also cause milder limb-girdle muscular dystrophy phenotypes. Using a combination of exome and Sanger sequencing in eight unrelated individuals, we present evidence that mutations in guanosine diphosphate mannose (GDP-mannose) pyrophosphorylase B (GMPPB) can result in muscular dystrophy variants with hypoglycosylated α-DG. GMPPB catalyzes the formation of GDP-mannose from GTP and mannose-1-phosphate. GDP-mannose is required for O-mannosylation of proteins, including α-DG, and it is the substrate of cytosolic mannosyltransferases. We found reduced α-DG glycosylation in the muscle biopsies of affected individuals and in available fibroblasts. Overexpression of wild-type GMPPB in fibroblasts from an affected individual partially restored glycosylation of α-DG. Whereas wild-type GMPPB localized to the cytoplasm, five of the identified missense mutations caused formation of aggregates in the cytoplasm or near membrane protrusions. Additionally, knockdown of the GMPPB ortholog in zebrafish caused structural muscle defects with decreased motility, eye abnormalities, and reduced glycosylation of α-DG. Together, these data indicate that GMPPB mutations are responsible for congenital and limb-girdle muscular dystrophies with hypoglycosylation of α-DG. © 2013 The American Society of Human Genetics.Funding for UK10K was provided by the Wellcome Trust under award WT091310

Exome Sequencing Identifies DYNC1H1 Variant Associated With Vertebral Abnormality and Spinal Muscular Atrophy With Lower Extremity Predominance.

BACKGROUND: Molecular diagnosis of the distal spinal muscular atrophies or distal hereditary motor neuropathies remains challenging due to clinical and genetic heterogeneity. Next generation sequencing offers potential for identifying de novo mutations of causative genes in isolated cases. PATIENT: We describe a 3.6 year old girl with congenital scoliosis, equinovarus and L5/S1 left hemivertebra who showed delayed walking and lower extremities atrophy. She was negative for SMN1 deletion testing and parents show no sign of disease. RESULTS: Whole exome sequencing of the affected girl showed a novel de novo heterozygous missense mutation c.1792C>T; (p.Arg598Cys) in the tail domain of the DYNC1H1 gene encoding for cytoplasmic dynein heavy chain 1. The mutation changed a highly conserved amino acid, and was absent from both parents. CONCLUSION: De novo mutations of DYNC1H1 have been found in cases of autosomal dominant mental retardation with neuronal migration defects. Dominantly inherited mutations of DYNC1H1 have been reported to cause spinal muscular atrophy with predominance of lower extremity involvement (SMA-LED) and Charcot-Marie-Tooth type 2O (CMT2O). This is the first report of a de novo DYNC1H1 mutation in the SMA-LED phenotype with a spinal deformity (lumbar hemi vertebrae). This case also demonstrates the power of next generation sequencing to discover de novo mutations at a genome-wide scale

Genome editing in animals: an overview

Genome editing is the process of making targeted modifications to the genome at site-specific locations. The most common methods for genome editing are sequence-specific programmable nucleases namely protein-guided zinc finger nucleases (ZFNs), transcriptional activator-like effector nucleases (TALENs) and CRISPR/Cas9 system. The class of RNA-guided endonucleases known as Cas9 from the microbial adaptive immune system CRISPR (clustered regularly interspaced short palindromic repeats) is the most rapidly developing genome editing technology. Prior to CRISPR/Cas9, genome editing approaches, like ZFNs or TALENs, relied upon the use of customizable DNA binding protein nucleases that required scientists to design and generate a new nuclease pair for every genomic target. Largely due to its simplicity and adaptability, CRISPR/Cas9 system has outpaced the other methods in its efficacy to obtain precise genetic modifications. With its unprecedented accuracy, variants of Cas9 like Cas9 nickase, Cpf1, Cas9-HF1, HypaCas9, and features like multiplexing, it has provided important advancements in animal agriculture. The rapid progress of genome editing in animals has been remarkable but there are many challenges ahead like ethical issues and public acceptance of genetically modified animals and their products. However, improving the efficiency, on-target specificity, and safety of genome editing will unlock a myriad of applications in animal sciences

Immunomodulatory effects of probiotics and prilled fat supplementation on immune genes expression and lymphocyte proliferation of transition stage Karan Fries cows

Background and Aim: Probiotics are the living microorganism which when administered improves the digestion and health of the animal. Saccharomyces cerevisiae (SC) improves the humoral and innate immunity of the animal. Prilled fat is a hydrogenated palm oil triglyceride which has been reported to promote the release of cytokines from macrophages. The aim of the study was to evaluate the immunomodulatory effect of probiotic and prilled fat during transition stage in Karan Fries (KF) cows. Materials and Methods: A total of 12 KF cows at 21 days prepartum were selected and divided into two groups of six animals each. The control group was fed as per the standard feeding practices and the supplemented group cows were supplemented daily with prilled fat at 100 g/cow, SC at 25 g/cow, and sweetener at 1 g/cow in addition to the standard feeding practices from -30 days of prepartum to 21 days of lactation. The sweetener was added to improve the palatability of the feed. The natural sweetener of an African plant leave had 105 times more sweetness than glucose with good aroma. The dry matter intake of the animal was recorded. Plasma samples were collected weekly from all cows for the analysis of blood metabolite beta-hydroxybutyric acid (BHBA). Lymphocytes were isolated from the blood for studying the expression of tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β) and for estimating lymphocyte proliferation index (LPI). Results: The upregulated IL-1β and TNF-α around calving might be possibly associated to the metabolic changes occurring during the transition period and suggest a higher degree of inflammation around parturition. High concentrations of BHBA caused increased expression and synthesis of the pro-inflammatory factors such as TNF-α and IL-1β in supplemented group in primary calf hepatocytes. The LPI was higher in supplemented group as compared to control which suggests a stimulatory effect of unsaturated fatty acids on mitogen-stimulated T-cell proliferation. Conclusion: Dietary supplementation of probiotics, prilled fat, and sweetener alleviated negative energy balance by stimulating feed intake and modulating hepatic lipid metabolism; and both of these additives improved the postpartum health (antioxidant status and immune function) of transition dairy cows

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Not AvailableTo better understand the molecular basis of corpus luteum (CL) development and function RNA-Seq was utilized to identify differentially expressed genes (DEGs) in porcine CL during different physiological stages of the estrous cycle viz. early (EL), mid (ML), late (LL) and regressed (R) luteal. Stage wise comparisons obtained 717 (EL vs. ML), 568 (EL vs. LL), 527 (EL vs. R), 786 (ML vs. LL), 474 (ML vs. R) and 534 (LL vs. R) DEGs with log2(FC) ≥1 and p < 0.05. The process of angiogenesis, steroidogenesis, signal transduction, translation, cell proliferation and tissue remodelling were significantly (p < 0.05) enriched in EL, ML and LL stages, where as apoptosis was most active in regressed stage. Pathway analysis revealed that most annotated genes were associated with lipid metabolism, translation, immune and endocrine system pathways depicting intra-luteal control of diverse CL function. The network analysis identified genes AR, FOS, CDKN1A, which were likely the novel hub genes regulating CL physiology.Not Availabl