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Lessel D, Rading K, Campbell SE, Thiele H, Altmüller J, Gordon LB, Kubisch C. A novel homozygous synonymous variant further expands the phenotypic spectrum of POLR3A-related pathologies. Am J Med Genet A 2021; 188:216-223. [PMID: 34611991 DOI: 10.1002/ajmg.a.62525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 08/21/2021] [Accepted: 09/06/2021] [Indexed: 12/18/2022]
Abstract
Pathogenic biallelic variants in POL3RA have been associated with different disorders characterized by progressive neurological deterioration. These include the 4H leukodystrophy syndrome (hypomyelination, hypogonadotropic hypogonadism, and hypodontia) and adolescent-onset progressive spastic ataxia, as well as Wiedemann-Rautenstrauch syndrome (WRS), a recognizable neonatal progeroid syndrome. The phenotypic differences between these disorders are thought to occur mainly due to different functional effects of underlying POLR3A variants. Here we present the detailed clinical course of a 37-year-old woman in whom we identified a homozygous synonymous POLR3A variant c.3336G>A resulting in leaky splicing r.[3336ins192, =, 3243_3336del94]. She presented at birth with intrauterine growth retardation, lipodystrophy, muscular hypotonia, and several WRS-like facial features, albeit without sparse hair and prominent scalp veins. She had no signs of developmental delay or intellectual disability. Over the years, above characteristic facial features, she showed severe postnatal growth retardation, global lipodystrophy, joint contractures, thoracic hypoplasia, scoliosis, anodontia, spastic quadriplegia, bilateral hearing loss, aphonia, hypogonadotropic hypogonadism, and cerebellar peduncles hyperintensities in brain imaging. These manifestations partially overlap the clinical features of the previously reported POLR3A-associated disorders, mostly mimicking the WRS. Thus, our study expands the POLR3A-mediated phenotypic spectrum and suggests existence of a phenotypic continuum underlying biallelic POLR3A variants.
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Affiliation(s)
- Davor Lessel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Katrin Rading
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Susan E Campbell
- Center for Gerontology and Healthcare Research, Brown University, Providence, Rhode Island, USA
| | - Holger Thiele
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Janine Altmüller
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Berlin Institute of Health, Charité-Universitätsmedizin Berlin, Core Facility Genomics, Berlin, Germany.,The Genomics unit, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Leslie B Gordon
- Department of Pediatrics, Division of Genetics, Hasbro Children's Hospital, Providence, Rhode Island, USA.,Warren Alpert Medical School, Brown University, Providence, Rhode Island, USA.,Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Christian Kubisch
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Lessel D, Wu D, Trujillo C, Ramezani T, Lessel I, Alwasiyah MK, Saha B, Hisama FM, Rading K, Goebel I, Schütz P, Speit G, Högel J, Thiele H, Nürnberg G, Nürnberg P, Hammerschmidt M, Zhu Y, Tong DR, Katz C, Martin GM, Oshima J, Prives C, Kubisch C. Dysfunction of the MDM2/p53 axis is linked to premature aging. J Clin Invest 2017; 127:3598-3608. [PMID: 28846075 DOI: 10.1172/jci92171] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 07/14/2017] [Indexed: 12/20/2022] Open
Abstract
The tumor suppressor p53, a master regulator of the cellular response to stress, is tightly regulated by the E3 ubiquitin ligase MDM2 via an autoregulatory feedback loop. In addition to its well-established role in tumorigenesis, p53 has also been associated with aging in mice. Several mouse models with aberrantly increased p53 activity display signs of premature aging. However, the relationship between dysfunction of the MDM2/p53 axis and human aging remains elusive. Here, we have identified an antiterminating homozygous germline mutation in MDM2 in a patient affected by a segmental progeroid syndrome. We show that this mutation abrogates MDM2 activity, thereby resulting in enhanced levels and stability of p53. Analysis of the patient's primary cells, genome-edited cells, and in vitro and in vivo analyses confirmed the MDM2 mutation's aberrant regulation of p53 activity. Functional data from a zebrafish model further demonstrated that mutant Mdm2 was unable to rescue a p53-induced apoptotic phenotype. Altogether, our findings indicate that mutant MDM2 is a likely driver of the observed segmental form of progeria.
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Affiliation(s)
- Davor Lessel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Danyi Wu
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Carlos Trujillo
- Genetics Unit, Dr. Erfan & Bagedo Hospital, Jeddah, Saudi Arabia
| | - Thomas Ramezani
- Institute of Developmental Biology, University of Cologne, Cologne, Germany
| | - Ivana Lessel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Mohammad K Alwasiyah
- Aziziah Maternity and Children's Hospital, Ministry of Health, Jeddah, Saudi Arabia
| | - Bidisha Saha
- Department of Pathology, University of Washington, Seattle, Washington, USA
| | - Fuki M Hisama
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Katrin Rading
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ingrid Goebel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Petra Schütz
- Institute of Human Genetics, University of Ulm, Ulm, Germany
| | - Günter Speit
- Institute of Human Genetics, University of Ulm, Ulm, Germany
| | - Josef Högel
- Institute of Human Genetics, University of Ulm, Ulm, Germany
| | | | | | - Peter Nürnberg
- Cologne Center for Genomics.,Center for Molecular Medicine Cologne, and.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Matthias Hammerschmidt
- Institute of Developmental Biology, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, and.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Yan Zhu
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - David R Tong
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Chen Katz
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - George M Martin
- Department of Pathology, University of Washington, Seattle, Washington, USA.,Molecular Biology Institute, UCLA, Los Angeles, California, USA
| | - Junko Oshima
- Department of Pathology, University of Washington, Seattle, Washington, USA.,Department of Medicine, Chiba University, Chiba, Japan
| | - Carol Prives
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Christian Kubisch
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute of Human Genetics, University of Ulm, Ulm, Germany
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