Article

Identification of a novel NOG gene mutation (P35S) in an Italian family with symphalangism.

C.S.S. Mendel Institute and University La Sapienza, Rome, Italy.
Human Mutation (Impact Factor: 5.05). 03/2002; 19(3):308. DOI: 10.1002/humu.9016
Source: PubMed

ABSTRACT Symphalangism (SYM or SYM1) is an autosomal dominant disorder characterized by multiple joint fusions. The disease is caused by mutations of the NOG gene, that maps to chromosome 17q22. So far, only six independent NOG mutations have been identified. We have analysed an Italian family in which father and son had bilateral symphalangism and detected a novel NOG mutation (P35S), originated in the father from a c.914C>T transition. A different mutation in the same codon (P35R) has been previously described. Comparison between different noggin gene hortologs shows that codon 35 is conserved. Therefore, this codon should play an important role in NOG gene function. This is the first mutation described for NOG after the initial report of NOG mutations being causative of SYM.

0 Bookmarks
 · 
108 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Growth and Differentiation Factor 5 (GDF5) is a secreted growth factor that belongs to the Bone Morphogenetic Protein (BMP) family and plays a pivotal role during limb development. GDF5 is a susceptibility gene for osteoarthritis (OA) and mutations in GDF5 are associated with a wide variety of skeletal malformations ranging from complex syndromes such as acromesomelic chondrodysplasias to isolated forms of brachydactylies or multiple synostoses syndrome 2 (SYNS2). Here, we report on a family with an autosomal dominant inherited combination of SYNS2 and additional brachydactyly type A1 (BDA1) caused by a single point mutation in GDF5 (p.W414R). Functional studies, including chondrogenesis assays with primary mesenchymal cells, luciferase reporter gene assays and Surface Plasmon Resonance analysis, of the GDF5(W414R) variant in comparison to other GDF5 mutations associated with isolated BDA1 (p.R399C) or SYNS2 (p.E491K) revealed a dual pathomechanism characterized by a gain- and loss-of-function at the same time. On the one hand insensitivity to the main GDF5 antagonist NOGGIN (NOG) leads to a GDF5 gain of function and subsequent SYNS2 phenotype. Whereas on the other hand, a reduced signaling activity, specifically via the BMP receptor type IA (BMPR1A), is likely responsible for the BDA1 phenotype. These results demonstrate that one mutation in the overlapping interface of antagonist and receptor binding site in GDF5 can lead to a GDF5 variant with pathophysiological relevance for both, BDA1 and SYNS2 development. Consequently, our study assembles another part of the molecular puzzle of how loss and gain of function mutations in GDF5 affect bone development in hands and feet resulting in specific types of brachydactyly and SYNS2. These novel insights into the biology of GDF5 might also provide further clues on the pathophysiology of OA.
    PLoS Genetics 10/2013; 9(10):e1003846. DOI:10.1371/journal.pgen.1003846 · 8.17 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We report on a patient with a clinical phenotype showing all the features of the multiple synostoses syndrome or the facioaudiosymphalangism syndrome, including symphalangism, condunction deafness, and the typical facies. Previously, it was shown that this condition is genetically heterogeneous with initially mutations described in the NOG gene, coding for Noggin, an extracellular antagonist of bone morphogenetic proteins. Noggin also interacts with growth differentiation factor 5 (GDF5), in which mutations have also been described in families with symphalangism. The latter is also the case for the BMP receptor BMPR1B to which GDF5 binds. Finally, a mutation in another growth factor, fibroblast growth factor 9, was found in a family with multiple synostoses syndrome. In our patient, we could, however, not show a causative mutation in any of these genes, providing evidence for further genetic heterogeneity of this syndrome.
    Clinical dysmorphology 09/2012; 22(1). DOI:10.1097/MCD.0b013e3283590986 · 0.47 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Bone Morphogenetic Proteins (BMPs) are secreted protein hormones that act as morphogens and exert essential roles during embryonic development of tissues and organs. Signaling by BMPs occurs via hetero-oligomerization of two types of serine/threonine kinase transmembrane receptors. Due to the small number of available receptors for a large number of BMP ligands ligand-receptor promiscuity presents an evident problem requiring additional regulatory mechanisms for ligand-specific signaling. Such additional regulation is achieved through a plethora of extracellular antagonists, among them members of the Chordin superfamily, that modulate BMP signaling activity by binding. The key-element in Chordin-related antagonists for interacting with BMPs is the von Willebrand type C (VWC) module, which is a small domain of about 50 to 60 residues occurring in many different proteins. Although a structure of the VWC domain of the Chordin-member Crossveinless 2 (CV2) bound to BMP-2 has been determined by X-ray crystallography, the molecular mechanism by which the VWC domain binds BMPs has remained unclear. Here we present the NMR structure of the Danio rerio CV2 VWC1 domain in its unbound state showing that the key features for high affinity binding to BMP-2 is a pre-oriented peptide loop.
    Molecules 10/2013; 18(10):11658-82. DOI:10.3390/molecules181011658 · 2.10 Impact Factor

Preview

Download
0 Downloads