1
|
Falb RJ, Müller AJ, Klein W, Grimmel M, Grasshoff U, Spranger S, Stöbe P, Gauck D, Kuechler A, Dikow N, Schwaibold EMC, Schmidt C, Averdunk L, Buchert R, Heinrich T, Prodan N, Park J, Kehrer M, Sturm M, Kelemen O, Hartmann S, Horn D, Emmerich D, Hirt N, Neumann A, Kristiansen G, Gembruch U, Haen S, Siebert R, Hentze S, Hoopmann M, Ossowski S, Waldmüller S, Beck-Wödl S, Gläser D, Tekesin I, Distelmaier F, Riess O, Kagan KO, Dufke A, Haack TB. Bi-allelic loss-of-function variants in KIF21A cause severe fetal akinesia with arthrogryposis multiplex. J Med Genet 2023; 60:48-56. [PMID: 34740919 PMCID: PMC9811090 DOI: 10.1136/jmedgenet-2021-108064] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 10/14/2021] [Indexed: 02/04/2023]
Abstract
BACKGROUND Fetal akinesia (FA) results in variable clinical presentations and has been associated with more than 166 different disease loci. However, the underlying molecular cause remains unclear in many individuals. We aimed to further define the set of genes involved. METHODS We performed in-depth clinical characterisation and exome sequencing on a cohort of 23 FA index cases sharing arthrogryposis as a common feature. RESULTS We identified likely pathogenic or pathogenic variants in 12 different established disease genes explaining the disease phenotype in 13 index cases and report 12 novel variants. In the unsolved families, a search for recessive-type variants affecting the same gene was performed; and in five affected fetuses of two unrelated families, a homozygous loss-of-function variant in the kinesin family member 21A gene (KIF21A) was found. CONCLUSION Our study underlines the broad locus heterogeneity of FA with well-established and atypical genotype-phenotype associations. We describe KIF21A as a new factor implicated in the pathogenesis of severe neurogenic FA sequence with arthrogryposis of multiple joints, pulmonary hypoplasia and facial dysmorphisms. This hypothesis is further corroborated by a recent report on overlapping phenotypes observed in Kif21a null piglets.
Collapse
Affiliation(s)
- Ruth J Falb
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Amelie J Müller
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | | | - Mona Grimmel
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Ute Grasshoff
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | | | - Petra Stöbe
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Darja Gauck
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Alma Kuechler
- Institute of Human Genetics, University Hospital Essen, Essen, Germany
| | - Nicola Dikow
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | | | | | - Luisa Averdunk
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Heinrich-Heine-University Dusseldorf, Dusseldorf, Germany
| | - Rebecca Buchert
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Tilman Heinrich
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Natalia Prodan
- Department of Women's Health, University Women's Hospital, Tuebingen, Germany
| | - Joohyun Park
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Martin Kehrer
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Marc Sturm
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Olga Kelemen
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | | | - Denise Horn
- Institute of Medical and Human Genetics, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Dirk Emmerich
- Practice for Ultrasound and Prenatal Medicine, Freiburg, Germany
| | - Nina Hirt
- Institute of Human Genetics, University Medical Center Freiburg, Freiburg, Germany
| | | | - Glen Kristiansen
- Institute of Pathology, Center for Integrated Oncology, University of Bonn, Bonn, Germany
| | - Ulrich Gembruch
- Department of Obstetrics and Prenatal Medicine, University Hospital Bonn, Bonn, Germany
| | - Susanne Haen
- Institute of Pathology and Neuropathology, University of Tuebingen, Tuebingen, Germany
| | - Reiner Siebert
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, Ulm, Germany
| | | | - Markus Hoopmann
- Department of Women's Health, University Women's Hospital, Tuebingen, Germany
| | - Stephan Ossowski
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Stephan Waldmüller
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Stefanie Beck-Wödl
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | | | | | - Felix Distelmaier
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Heinrich-Heine-University Dusseldorf, Dusseldorf, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany,Centre for Rare Diseases, University of Tuebingen, Tuebingen, Germany
| | - Karl-Oliver Kagan
- Department of Women's Health, University Women's Hospital, Tuebingen, Germany
| | - Andreas Dufke
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany,Centre for Rare Diseases, University of Tuebingen, Tuebingen, Germany
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany,Centre for Rare Diseases, University of Tuebingen, Tuebingen, Germany
| |
Collapse
|
2
|
Liu YC, Wierbowski BM, Salic A. Hedgehog pathway modulation by glypican 3-conjugated heparan sulfate. J Cell Sci 2022; 135:274739. [PMID: 35142364 PMCID: PMC8977055 DOI: 10.1242/jcs.259297] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 02/04/2022] [Indexed: 11/20/2022] Open
Abstract
Glypicans are a family of cell surface heparan sulfate proteoglycans that play critical roles in multiple cell signaling pathways. Glypicans consist of a globular core, an unstructured stalk modified with sulfated glycosaminoglycan chains, and a glycosylphosphatidylinositol anchor. Though these structural features are conserved, their individual contribution to glypican function remains obscure. Here, we investigate how glypican 3 (GPC3), which is mutated in Simpson-Golabi-Behmel tissue overgrowth syndrome, regulates Hedgehog signaling. We find that GPC3 is necessary for the Hedgehog response, surprisingly controlling a downstream signal transduction step. Purified GPC3 ectodomain rescues signaling when artificially recruited to the surface of GPC3-deficient cells but has dominant-negative activity when unattached. Strikingly, the purified stalk, modified with heparan sulfate but not chondroitin sulfate, is necessary and sufficient for activity. Our results demonstrate a novel function for GPC3-associated heparan sulfate and provide a framework for the functional dissection of glycosaminoglycans by in vivo biochemical complementation. This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Yulu Cherry Liu
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.,Department of Biology, Hood College, Frederick, MD 21701, USA
| | | | - Adrian Salic
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
3
|
Zhao S, Wu C, Gao Z, Li X, Guo Z, Wang Z. Notch signaling governs the expression of glypican Dally to define the stem cell niche. Biol Open 2020; 9:bio.047696. [PMID: 31826854 PMCID: PMC6994927 DOI: 10.1242/bio.047696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Extracellular glypicans play pivotal roles in organogenesis, stem cell maintenance and cancer development. However, the growth phenotypes associated with different levels of glypican are not consistent in development or tumorigenesis. This requires clarification on how the spatial patterns of glypican relate to the distribution of signaling molecules in different cellular contexts, and how glypican expression is regulated. We have previously reported that Dally, one of the glypican members in Drosophila, is required in the niche for the maintenance of germline stem cells (GSCs) via short-range BMP signaling in ovary. However, the regulatory mechanism of glypican pattern in the ovarian stem cell niche remains elusive. Our current data demonstrate that the Notch pathway is genetically upstream of Dally and its function to maintain GSCs relies on Dally expression. Combining yeast and fruit fly genetics, we illustrate that Dally is under the transcriptional control of Notch signaling via the transcription factor Su(H). Further, we assayed human glypicans and disease-associated variants in Drosophila ovary, which can serve as an effective system to evaluate the structure–function relationship of human homologs. Summary: Spatial regulation of a cell surface glycoprotein defines the territory of germline stem cells.
Collapse
Affiliation(s)
- Songhua Zhao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100049, China.,The University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chan Wu
- The University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiyang Gao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100049, China
| | - Xin Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100049, China
| | - Zheng Guo
- The University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaohui Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100049, China .,The University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
4
|
Brioude F, Toutain A, Giabicani E, Cottereau E, Cormier-Daire V, Netchine I. Overgrowth syndromes - clinical and molecular aspects and tumour risk. Nat Rev Endocrinol 2019; 15:299-311. [PMID: 30842651 DOI: 10.1038/s41574-019-0180-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Overgrowth syndromes are a heterogeneous group of rare disorders characterized by generalized or segmental excessive growth commonly associated with additional features, such as visceromegaly, macrocephaly and a large range of various symptoms. These syndromes are caused by either genetic or epigenetic anomalies affecting factors involved in cell proliferation and/or the regulation of epigenetic markers. Some of these conditions are associated with neurological anomalies, such as cognitive impairment or autism. Overgrowth syndromes are frequently associated with an increased risk of cancer (embryonic tumours during infancy or carcinomas during adulthood), but with a highly variable prevalence. Given this risk, syndrome-specific tumour screening protocols have recently been established for some of these conditions. Certain specific clinical traits make it possible to discriminate between different syndromes and orient molecular explorations to determine which molecular tests to conduct, despite the syndromes having overlapping clinical features. Recent advances in molecular techniques using next-generation sequencing approaches have increased the number of patients with an identified molecular defect (especially patients with segmental overgrowth). This Review discusses the clinical and molecular diagnosis, tumour risk and recommendations for tumour screening for the most prevalent generalized and segmental overgrowth syndromes.
Collapse
Affiliation(s)
- Frédéric Brioude
- Sorbonne Université, INSERM UMR_S938, Centre de Recherche Saint Antoine, AP-HP Hôpital Trousseau, Paris, France.
| | - Annick Toutain
- CHU de Tours, Hôpital Bretonneau, Service de Génétique, INSERM UMR1253, iBrain, Université de Tours, Faculté de Médecine, Tours, France
| | - Eloise Giabicani
- Sorbonne Université, INSERM UMR_S938, Centre de Recherche Saint Antoine, AP-HP Hôpital Trousseau, Paris, France
| | - Edouard Cottereau
- CHU de Tours, Hôpital Bretonneau, Service de Génétique, Tours, France
| | - Valérie Cormier-Daire
- Service de génétique clinique, Université Paris Descartes-Sorbonne Paris Cité, INSERM UMR1163, Institut Imagine, Hôpital Necker-Enfants Malades, Paris, France
| | - Irene Netchine
- Sorbonne Université, INSERM UMR_S938, Centre de Recherche Saint Antoine, AP-HP Hôpital Trousseau, Paris, France
| |
Collapse
|
5
|
Vuillaume ML, Moizard MP, Rossignol S, Cottereau E, Vonwill S, Alessandri JL, Busa T, Colin E, Gérard M, Giuliano F, Lambert L, Lefevre M, Kotecha U, Nampoothiri S, Netchine I, Raynaud M, Brioude F, Toutain A. Mutation update for the GPC3 gene involved in Simpson-Golabi-Behmel syndrome and review of the literature. Hum Mutat 2018; 39:790-805. [PMID: 29637653 DOI: 10.1002/humu.23428] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 03/22/2018] [Accepted: 04/02/2018] [Indexed: 11/08/2022]
Abstract
Simpson-Golabi-Behmel syndrome (SGBS) is an X-linked multiple congenital anomalies and overgrowth syndrome caused by a defect in the glypican-3 gene (GPC3). Until now, GPC3 mutations have been reported in isolated cases or small series and the global genotypic spectrum of these mutations has never been delineated. In this study, we review the 57 previously described GPC3 mutations and significantly expand this mutational spectrum with the description of 29 novel mutations. Compiling our data and those of the literature, we provide an overview of 86 distinct GPC3 mutations identified in 120 unrelated families, ranging from single nucleotide variations to complex genomic rearrangements and dispersed throughout the entire coding region of GPC3. The vast majority of them are deletions or truncating mutations (frameshift, nonsense mutations) predicted to result in a loss-of-function. Missense mutations are rare and the two which were functionally characterized, impaired GPC3 function by preventing GPC3 cleavage and cell surface addressing respectively. This report by describing for the first time the wide mutational spectrum of GPC3 could help clinicians and geneticists in interpreting GPC3 variants identified incidentally by high-throughput sequencing technologies and also reinforces the need for functional validation of non-truncating mutations (missense, in frame mutations, duplications).
Collapse
Affiliation(s)
- Marie-Laure Vuillaume
- Service de Génétique, CHU de Tours, Hôpital Bretonneau, Tours, France.,INSERM UMR_U930, Faculté de Médecine, Université de Tours, Tours, France
| | - Marie-Pierre Moizard
- Service de Génétique, CHU de Tours, Hôpital Bretonneau, Tours, France.,INSERM UMR_U930, Faculté de Médecine, Université de Tours, Tours, France
| | - Sylvie Rossignol
- Unité d'explorations fonctionnelles endocriniennes, CHU Paris Est, Hôpital d'Enfants Armand-Trousseau, Paris, France.,Service de génétique médicale, CHU de Strasbourg, Hôpital de Hautepierre, Strasbourg, France
| | - Edouard Cottereau
- Service de Génétique, CHU de Tours, Hôpital Bretonneau, Tours, France
| | - Sandrine Vonwill
- Service de Génétique, CHU de Tours, Hôpital Bretonneau, Tours, France.,INSERM UMR_U930, Faculté de Médecine, Université de Tours, Tours, France
| | | | - Tiffany Busa
- Unité de Génétique Clinique, Département de génétique médicale, Hôpital de la Timone, CHU de Marseille, Marseille, France
| | - Estelle Colin
- Département de biochimie et génétique, CHU d'Angers, Angers, France
| | - Marion Gérard
- Service de génétique, CHU de Caen, Hôpital Clémenceau, Avenue Georges Clémenceau, Caen, France
| | - Fabienne Giuliano
- Service de génétique médicale, CHU de Nice, Hôpital l'Archet 2, Nice, France
| | - Laetitia Lambert
- Service de Génétique Clinique, Hôpital d'Enfants, CHU de Nancy, Rue du Morvan, Vandoeuvre-Lès-Nancy, France
| | - Mathilde Lefevre
- Centre de génétique, Hôpital d'enfants, CHU Dijon Bourgogne, Dijon, France
| | - Udhaya Kotecha
- Center of Medical Genetics, Sir Ganga Ram Hospital, Rajinder Nagar, New Delhi, India
| | - Sheela Nampoothiri
- Department of Pediatric Genetics, Amrita Institute of Medical Sciences and Research Center, AIMS Poneakara P O, Cochin, Kerala, India
| | - Irène Netchine
- Unité d'explorations fonctionnelles endocriniennes, CHU Paris Est, Hôpital d'Enfants Armand-Trousseau, Paris, France
| | - Martine Raynaud
- Service de Génétique, CHU de Tours, Hôpital Bretonneau, Tours, France.,INSERM UMR_U930, Faculté de Médecine, Université de Tours, Tours, France
| | - Frédéric Brioude
- Unité d'explorations fonctionnelles endocriniennes, CHU Paris Est, Hôpital d'Enfants Armand-Trousseau, Paris, France
| | - Annick Toutain
- Service de Génétique, CHU de Tours, Hôpital Bretonneau, Tours, France.,INSERM UMR_U930, Faculté de Médecine, Université de Tours, Tours, France
| |
Collapse
|
6
|
Das Bhowmik A, Dalal A. Whole exome sequencing identifies a novel frameshift mutation in GPC3 gene in a patient with overgrowth syndrome. Gene 2015; 572:303-6. [DOI: 10.1016/j.gene.2015.08.053] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 08/20/2015] [Accepted: 08/21/2015] [Indexed: 02/03/2023]
|
7
|
Filmus J, Capurro M. The role of glypicans in Hedgehog signaling. Matrix Biol 2014; 35:248-52. [PMID: 24412155 DOI: 10.1016/j.matbio.2013.12.007] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 12/18/2013] [Accepted: 12/18/2013] [Indexed: 01/13/2023]
Abstract
Glypicans (GPCs) are a family of proteoglycans that are bound to the cell surface by a glycosylphosphatidylinositol anchor. Six glypicans have been found in the mammalian genome (GPC1 to GPC6). GPCs regulate several signaling pathways, including the pathway triggered by Hedgehogs (Hhs). This regulation, which could be stimulatory or inhibitory, occurs at the signal reception level. In addition, GPCs have been shown to be involved in the formation of Hh gradients in the imaginal wing disks in Drosophila. In this review we will discuss the role of various glypicans in specific developmental events in the embryo that are regulated by Hh signaling. In addition, we will discuss the mechanism by which loss-of-function GPC3 mutations alter Hh signaling in the Simpson-Golabi-Behmel overgrowth syndrome, and the molecular basis of the GPC5-induced stimulation of Hh signaling and tumor progression in rhabdomyosarcomas.
Collapse
Affiliation(s)
- Jorge Filmus
- Platform of Biological Sciences, Sunnybrook Research Institute, ON, Canada; Dept. of Medical Biophysics, University of Toronto, ON, Canada.
| | - Mariana Capurro
- Platform of Biological Sciences, Sunnybrook Research Institute, ON, Canada; Dept. of Medical Biophysics, University of Toronto, ON, Canada
| |
Collapse
|
8
|
Dwivedi PP, Lam N, Powell BC. Boning up on glypicans-opportunities for new insights into bone biology. Cell Biochem Funct 2013; 31:91-114. [DOI: 10.1002/cbf.2939] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 11/09/2012] [Accepted: 11/16/2012] [Indexed: 01/01/2023]
Affiliation(s)
| | - N. Lam
- Craniofacial Research Group; Women's and Children's Health Research Institute; North Adelaide; South Australia; Australia
| | | |
Collapse
|
9
|
George AM, Taylor J, Love DR. Microdeletions in 16p11.2 and 13q31.3 associated with developmental delay and generalized overgrowth. GENETICS AND MOLECULAR RESEARCH 2012; 11:3133-7. [PMID: 23007991 DOI: 10.4238/2012.september.3.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Chromosome microarray analysis of patients with developmental delay has provided evidence of small deletions or duplications associated with this clinical phenotype. In this context, a 7.1- to 8.7-Mb interstitial deletion of chromosome 16 is well documented, but within this interval a rare 200-kb deletion has recently been defined that appears to be associated with obesity, or developmental delay together with overgrowth. We report a patient carrying this rare deletion, who falls into the latter clinical category, but who also carries a second very rare deletion in 13q31.3. It remains unclear if this maternally inherited deletion acts as a second copy number variation leading to pathogenic variation, or is non-causal and the true modifiers are yet to be determined.
Collapse
Affiliation(s)
- A M George
- Diagnostic Genetics, LabPlus, Auckland City Hospital, Auckland, New Zealand
| | | | | |
Collapse
|
10
|
Structure of the protein core of the glypican Dally-like and localization of a region important for hedgehog signaling. Proc Natl Acad Sci U S A 2011; 108:13112-7. [PMID: 21828006 DOI: 10.1073/pnas.1109877108] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Glypicans are heparan sulfate proteoglycans that modulate the signaling of multiple growth factors active during animal development, and loss of glypican function is associated with widespread developmental abnormalities. Glypicans consist of a conserved, approximately 45-kDa N-terminal protein core region followed by a stalk region that is tethered to the cell membrane by a glycosyl-phosphatidylinositol anchor. The stalk regions are predicted to be random coil but contain a variable number of attachment sites for heparan sulfate chains. Both the N-terminal protein core and the heparan sulfate attachments are important for glypican function. We report here the 2.4-Å crystal structure of the N-terminal protein core region of the Drosophila glypican Dally-like (Dlp). This structure reveals an elongated, α-helical fold for glypican core regions that does not appear homologous to any known structure. The Dlp core protein is required for normal responsiveness to Hedgehog (Hh) signals, and we identify a localized region on the Dlp surface important for mediating its function in Hh signaling. Purified Dlp protein core does not, however, interact appreciably with either Hh or an Hh:Ihog complex.
Collapse
|
11
|
Abstract
Geneticists estimate that 5% to 10% of all cancers diagnosed in the pediatric age range occur in children born with a genetic mutation that directly increases their lifetime risk for neoplasia. However, despite the fact that only a fraction of cancers in children occur as a result of an identified inherited predisposition, characterizing genetic mutations responsible for increased cancer risk in such syndromes has resulted in a profound understanding of relevant molecular pathways involved in carcinogenesis and/or resistance to neoplasia. Importantly, because most cancer predisposition syndromes result in an increased risk of a small number of defined malignancies, personalized prophylactic surveillance and preventive measures can be implemented in affected patients. Lastly, many of the same genetic targets identified from cancer-prone families are mechanistically involved in the majority of sporadic cancers in adults and children, thereby underscoring the clinical relevance of knowledge gained from these defined syndromes and introducing novel therapeutic opportunities to the broader oncologic community. This review highlights the clinical and genetic features of many of the known constitutional genetic syndromes that predispose to malignancy in children and young adults.
Collapse
|