68 research outputs found

    Bi-allelic variants in IPO8 cause a connective tissue disorder associated with cardiovascular defects, skeletal abnormalities, and immune dysregulation.

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    Dysregulated transforming growth factor TGF-β signaling underlies the pathogenesis of genetic disorders affecting the connective tissue such as Loeys-Dietz syndrome. Here, we report 12 individuals with bi-allelic loss-of-function variants in IPO8 who presented with a syndromic association characterized by cardio-vascular anomalies, joint hyperlaxity, and various degree of dysmorphic features and developmental delay as well as immune dysregulation; the individuals were from nine unrelated families. Importin 8 belongs to the karyopherin family of nuclear transport receptors and was previously shown to mediate TGF-β-dependent SMADs trafficking to the nucleus in vitro. The important in vivo role of IPO8 in pSMAD nuclear translocation was demonstrated by CRISPR/Cas9-mediated inactivation in zebrafish. Consistent with IPO8's role in BMP/TGF-β signaling, ipo8-/- zebrafish presented mild to severe dorso-ventral patterning defects during early embryonic development. Moreover, ipo8-/- zebrafish displayed severe cardiovascular and skeletal defects that mirrored the human phenotype. Our work thus provides evidence that IPO8 plays a critical and non-redundant role in TGF-β signaling during development and reinforces the existing link between TGF-β signaling and connective tissue defects

    SCUBE3 loss-of-function causes a recognizable recessive developmental disorder due to defective bone morphogenetic protein signaling

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    Signal peptide-CUB-EGF domain-containing protein 3 (SCUBE3) is a member of a small family of multifunctional cell surface-anchored glycoproteins functioning as co-receptors for a variety of growth factors. Here we report that bi-allelic inactivating variants in SCUBE3 have pleiotropic consequences on development and cause a previously unrecognized syndromic disorder. Eighteen affected individuals from nine unrelated families showed a consistent phenotype characterized by reduced growth, skeletal features, distinctive craniofacial appearance, and dental anomalies. In vitro functional validation studies demonstrated a variable impact of disease-causing variants on transcript processing, protein secretion and function, and their dysregulating effect on bone morphogenetic protein (BMP) signaling. We show that SCUBE3 acts as a BMP2/BMP4 co-receptor, recruits the BMP receptor complexes into raft microdomains, and positively modulates signaling possibly by augmenting the specific interactions between BMPs and BMP type I receptors. Scube3(-/-) mice showed craniofacial and dental defects, reduced body size, and defective endochondral bone growth due to impaired BMP-mediated chondrogenesis and osteogenesis, recapitulating the human disorder. Our findings identify a human disease caused by defective function of a member of the SCUBE family, and link SCUBE3 to processes controlling growth, morphogenesis, and bone and teeth development through modulation of BMP signaling.Genetics of disease, diagnosis and treatmen

    Heterozygous ANKRD17 loss-of-function variants cause a syndrome with intellectual disability, speech delay, and dysmorphism

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    ANKRD17 is an ankyrin repeat-containing protein thought to play a role in cell cycle progression, whose ortholog in Drosophila functions in the Hippo pathway as a co-factor of Yorkie. Here, we delineate a neurodevelopmental disorder caused by de novo heterozygous ANKRD17 variants. The mutational spectrum of this cohort of 34 individuals from 32 families is highly suggestive of haploinsufficiency as the underlying mechanism of disease, with 21 truncating or essential splice site variants, 9 missense variants, 1 in-frame insertion-deletion, and 1 microdeletion (1.16 Mb). Consequently, our data indicate that loss of ANKRD17 is likely the main cause of phenotypes previously associated with large multi-gene chromosomal aberrations of the 4q13.3 region. Protein modeling suggests that most of the missense variants disrupt the stability of the ankyrin repeats through alteration of core structural residues. The major phenotypic characteristic of our cohort is a variable degree of developmental delay/intellectual disability, particularly affecting speech, while additional features include growth failure, feeding difficulties, non-specific MRI abnormalities, epilepsy and/or abnormal EEG, predisposition to recurrent infections (mostly bacterial), ophthalmological abnormalities, gait/balance disturbance, and joint hypermobility. Moreover, many individuals shared similar dysmorphic facial features. Analysis of single-cell RNA-seq data from the developing human telencephalon indicated ANKRD17 expression at multiple stages of neurogenesis, adding further evidence to the assertion that damaging ANKRD17 variants cause a neurodevelopmental disorder.Neurolog

    PPA2-associated sudden cardiac death: extending the clinical and allelic spectrum in 20 new families

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    Purpose Biallelic hypomorphic variants in PPA2, encoding the mitochondrial inorganic pyrophosphatase 2 protein, have been recently identified in individuals presenting with sudden cardiac death, occasionally triggered by alcohol intake or a viral infection. Here we report 20 new families harboring PPA2 variants. Methods Synthesis of clinical and molecular data concerning 34 individuals harboring five previously reported PPA2 variants and 12 novel variants, 11 of which were functionally characterized. Results Among the 34 individuals, only 6 remain alive. Twenty-three died before the age of 2 years while five died between 14 and 16 years. Within these 28 cases, 15 died of sudden cardiac arrest and 13 of acute heart failure. One case was diagnosed prenatally with cardiomyopathy. Four teenagers drank alcohol before sudden cardiac arrest. Progressive neurological signs were observed in 2/6 surviving individuals. For 11 variants, recombinant PPA2 enzyme activities were significantly decreased and sensitive to temperature, compared to wild-type PPA2 enzyme activity. Conclusion We expand the clinical and mutational spectrum associated with PPA2 dysfunction. Heart failure and sudden cardiac arrest occur at various ages with inter- and intrafamilial phenotypic variability, and presentation can include progressive neurological disease. Alcohol intake can trigger cardiac arrest and should be strictly avoided

    Effect of sewage water on seed germination and vigour index of different varieties of groundnut (Arachis Hypogaea L.)

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    Abstract: The study has been focused on the investigation on ground nut (Arachis hypogea) fields influenced by sewage water. Sewage water sampled in and around Mysore city and analyzed for physicochemical parameters. Different concentrations such as 1, 5, 10, 25, 50, 70 and 100% of sewage water on seed germination and vigour index of Arachis hypogea verities such as DH – 2 – 30, ICJS – 11, JL – 24, K – 134, TMV – 2 and VRI – 2 were studied. From the recorded observation it is concluded that the sewage water diluted to 25% concentration for irrigation of groundnut enhances germination percentage and vigour index in K – 134 variety which is more susceptible than other tested varieties

    Biobeneficiation of iron ores

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    Utilization of aerobic and anaerobic microorganisms in iron ore beneficiation is discussed. Microorganisms such as Paenibacillus polymyxa, Bacillus subtilis, Saccharomyces cerevisiae (yeast) and Desulfovibrio desulfuricans (SRB) are capable of significantly altering the surface chemical behavior of iron ore minerals such as hematite, corundum, calcite, quartz and apatite. Differing mineral surface affinities of microbial cells and metabolic products such as proteins and polysaccharides can be utilized to induce their flotation or flocculation. Mineral-specific bioreagents such as proteins are generated when bacteria and yeast were grown in the presence of hematite, corundum, calcite, quartz and apatite. This study has demonstrated the utility and amenability of microbially-induced mineral beneficiation of iron ores through bacterial and yeast cells and their metabolic byproducts
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