9
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      FLNA mutations in surviving males presenting with connective tissue findings: two new case reports and review of the literature

      case-report

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Background

          Mutations in the X-linked gene filamin A ( FLNA), encoding the actin-binding protein FLNA, cause a wide spectrum of connective tissue, skeletal, cardiovascular and/or gastrointestinal manifestations. Males are typically more severely affected than females with common pre- or perinatal death.

          Case presentation

          We provide a genotype- and phenotype-oriented literature overview of FLNA hemizygous mutations and report on two live-born male FLNA mutation carriers. Firstly, we identified a de novo, missense mutation (c.238C > G, p.(Leu80Val)) in a five-year old Indian boy who presented with periventricular nodular heterotopia, increased skin laxity, joint hypermobility, mitral valve prolapse with regurgitation and marked facial features (e.g. a flat face, orbital fullness, upslanting palpebral fissures and low-set ears). Secondly, we identified two cis-located FLNA mutations (c.7921C > G, p.(Pro2641Ala); c.7923delC, p.(Tyr2642Thrfs*63)) in a Bosnian patient with Ehlers-Danlos syndrome-like features such as skin translucency and joint hypermobility. This patient also presented with brain anomalies, pectus excavatum, mitral valve prolapse, pulmonary hypertension and dilatation of the pulmonary arteries. He died from heart failure in his second year of life.

          Conclusions

          These two new cases expand the list of live-born FLNA mutation-positive males with connective tissue disease from eight to ten, contributing to a better knowledge of the genetic and phenotypic spectrum of FLNA-related disease.

          Electronic supplementary material

          The online version of this article (10.1186/s12881-018-0655-0) contains supplementary material, which is available to authorized users.

          Related collections

          Most cited references43

          • Record: found
          • Abstract: found
          • Article: not found

          Mutations in filamin 1 prevent migration of cerebral cortical neurons in human periventricular heterotopia.

          Long-range, directed migration is particularly dramatic in the cerebral cortex, where postmitotic neurons generated deep in the brain migrate to form layers with distinct form and function. In the X-linked dominant human disorder periventricular heterotopia (PH), many neurons fail to migrate and persist as nodules lining the ventricular surface. Females with PH present with epilepsy and other signs, including patent ductus arteriosus and coagulopathy, while hemizygous males die embryonically. We have identified the PH gene as filamin 1 (FLN1), which encodes an actin-cross-linking phosphoprotein that transduces ligand-receptor binding into actin reorganization, and which is required for locomotion of many cell types. FLN1 shows previously unrecognized, high-level expression in the developing cortex, is required for neuronal migration to the cortex, and is essential for embryogenesis.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Structural basis of filamin A functions

            Filamin A (FLNa) can effect orthogonal branching of F-actin and bind many cellular constituents. FLNa dimeric subunits have N-terminal spectrin family F-actin binding domains (ABDs) and an elongated flexible segment of 24 immunoglobulin (Ig) repeats. We generated a library of FLNa fragments to examine their F-actin binding to define the structural properties of FLNa that enable its various functions. We find that Ig repeats 9–15 contain an F-actin–binding domain necessary for high avidity F-actin binding. Ig repeats 16–24, where most FLNa-binding partners interact, do not bind F-actin, and thus F-actin does not compete with Ig repeat 23 ligand, FilGAP. Ig repeats 16–24 have a compact structure that suggests their unfolding may accommodate pre-stress–mediated stiffening of F-actin networks, partner binding, mechanosensing, and mechanoprotection properties of FLNa. Our results also establish the orientation of FLNa dimers in F-actin branching. Dimerization, mediated by FLNa Ig repeat 24, accounts for rigid high-angle FLNa/F-actin branching resistant to bending by thermal forces, and high avidity F-actin binding and cross-linking.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Localized mutations in the gene encoding the cytoskeletal protein filamin A cause diverse malformations in humans.

              Remodeling of the cytoskeleton is central to the modulation of cell shape and migration. Filamin A, encoded by the gene FLNA, is a widely expressed protein that regulates re-organization of the actin cytoskeleton by interacting with integrins, transmembrane receptor complexes and second messengers. We identified localized mutations in FLNA that conserve the reading frame and lead to a broad range of congenital malformations, affecting craniofacial structures, skeleton, brain, viscera and urogenital tract, in four X-linked human disorders: otopalatodigital syndrome types 1 (OPD1; OMIM 311300) and 2 (OPD2; OMIM 304120), frontometaphyseal dysplasia (FMD; OMIM 305620) and Melnick-Needles syndrome (MNS; OMIM 309350). Several mutations are recurrent, and all are clustered into four regions of the gene: the actin-binding domain and rod domain repeats 3, 10 and 14/15. Our findings contrast with previous observations that loss of function of FLNA is embryonic lethal in males but manifests in females as a localized neuronal migration disorder, called periventricular nodular heterotopia (PVNH; refs. 3-6). The patterns of mutation, X-chromosome inactivation and phenotypic manifestations in the newly described mutations indicate that they have gain-of-function effects, implicating filamin A in signaling pathways that mediate organogenesis in multiple systems during embryonic development.
                Bookmark

                Author and article information

                Contributors
                Elyssa.cannaerts@uantwerpen.be
                dranju2003@yahoo.co.in
                hmensuda@gmail.com
                Maaike.alaerts@uantwerpen.be
                Dorien.schepers@uantwerpen.be
                Lut.vanlaer@uantwerpen.be
                girishkatta@gmail.com
                ivahojsak@gmail.com
                Bart.loeys@uantwerpen.be
                +32 3 275 97 74 , Aline.verstraeten@uantwerpen.be
                Journal
                BMC Med Genet
                BMC Med. Genet
                BMC Medical Genetics
                BioMed Central (London )
                1471-2350
                8 August 2018
                8 August 2018
                2018
                : 19
                : 140
                Affiliations
                [1 ]ISNI 0000 0001 0790 3681, GRID grid.5284.b, Center of Medical Genetics, Faculty of Medicine and Health Sciences, , University of Antwerp and Antwerp University Hospital, ; Prins Boudewijnlaan 43, 2650 Antwerp, Belgium
                [2 ]ISNI 0000 0001 0571 5193, GRID grid.411639.8, Department of Medical Genetics, Kasturba Medical College, , Manipal University, ; Manipal, India
                [3 ]ISNI 0000 0001 0682 9061, GRID grid.412410.2, Department of Endocrinology, Metabolic Diseases and Genetics, , University Clinical Center Tuzla, Children’s hospital, ; Tuzla, Bosnia and Herzegovina
                [4 ]ISNI 0000 0001 0657 4636, GRID grid.4808.4, Referral Center for Pediatric Gastroenterology and Nutrition, Children’s Hospital Zagreb, , University of Zagreb, School of Medicine, ; Zagreb, Croatia
                [5 ]ISNI 0000 0004 0444 9382, GRID grid.10417.33, Department of Human Genetics, , Radboud University Nijmegen Medical Center, ; Nijmegen, The Netherlands
                Author information
                http://orcid.org/0000-0003-4740-8014
                Article
                655
                10.1186/s12881-018-0655-0
                6083619
                30089473
                e46b008c-4945-4a10-968b-d442200ac68f
                © The Author(s). 2018

                Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License ( http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

                History
                : 19 February 2018
                : 24 July 2018
                Funding
                Funded by: FundRef http://dx.doi.org/10.13039/501100007660, Universiteit Antwerpen;
                Award ID: Lanceringsproject 25777
                Award Recipient :
                Funded by: FundRef http://dx.doi.org/10.13039/501100003130, Fonds Wetenschappelijk Onderzoek;
                Award ID: G.0221.12
                Award ID: G.0356.17
                Award Recipient :
                Funded by: FundRef http://dx.doi.org/10.13039/501100002996, Hartstichting;
                Award ID: 2013T093 BAV
                Award Recipient :
                Funded by: FundRef http://dx.doi.org/10.13039/501100001674, Fondation Leducq;
                Award ID: MIBAVA - Leducq 12CVD03
                Award Recipient :
                Funded by: FundRef http://dx.doi.org/10.13039/100010663, H2020 European Research Council;
                Award ID: ERC - StG-2012-30972-BRAVE
                Award Recipient :
                Categories
                Case Report
                Custom metadata
                © The Author(s) 2018

                Genetics
                periventricular nodular heterotopia,live-born males,filaminopathy,connective tissue disease

                Comments

                Comment on this article