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Wilke MVMB, Wick M, Schwab TL, Starosta RT, Clark KJ, Connolly HM, Klee EW. Nuclear Abnormalities in LMNA p.(Glu2Lys) Variant Segregating with LMNA-Associated Cardiocutaneous Progeria Syndrome. Genes (Basel) 2024; 15:112. [PMID: 38255001 PMCID: PMC10815864 DOI: 10.3390/genes15010112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/10/2024] [Accepted: 01/15/2024] [Indexed: 01/24/2024] Open
Abstract
The LMNA gene encodes lamin A and lamin C, which play important roles in nuclear organization. Pathogenic variants in LMNA cause laminopathies, a group of disorders with diverse phenotypes. There are two main groups of disease-causing variants: missense variants affecting dimerization and intermolecular interactions, and heterozygous substitutions activating cryptic splice sites. These variants lead to different disorders, such as dilated cardiomyopathy and Hutchinson-Gilford progeria (HGP). Among these, the phenotypic terms for LMNA-associated cardiocutaneous progeria syndrome (LCPS), which does not alter lamin A processing and has an older age of onset, have been described. Here, we present the workup of an LMNA variant of uncertain significance, NM_170707.2 c. 4G>A, p.(Glu2Lys), in a 36-year-old female with severe calcific aortic stenosis, a calcified mitral valve, premature aging, and a family history of similar symptoms. Due to the uncertainty of in silico predictions for this variant, an assessment of nuclear morphology was performed using the immunocytochemistry of stable cell lines to indicate whether the p.(Glu2Lys) had a similar pathogenic mechanism as a previously described pathogenic variant associated with LCPS, p.Asp300Gly. Indirect immunofluorescence analysis of nuclei from stable cell lines showed abnormal morphology, including lobulation and occasional ringed nuclei. Relative to the controls, p.Glu2Lys and p.Asp300Gly nuclei had significantly (p < 0.001) smaller average nuclear areas than controls (mean = 0.10 units, SD = 0.06 for p.Glu2Lys; and mean = 0.09 units, SD = 0.05 for p.Asp300Gly versus mean = 0.12, SD = 0.05 for WT). After functional studies and segregation studies, this variant was upgraded to likely pathogenic. In summary, our findings suggest that p.Glu2Lys impacts nuclear morphology in a manner comparable to what was observed in p.Asp300Gly cells, indicating that the variant is the likely cause of the LCPS segregating within this family.
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Affiliation(s)
| | - Myra Wick
- Department of Obstetrics and Gynecology, Mayo Clinic, Rochester, MN 55905, USA;
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN 55905, USA
| | - Tanya L. Schwab
- Department of Molecular Hematology, Mayo Clinic, Rochester, MN 55905, USA
| | - Rodrigo Tzovenos Starosta
- Division of Medical Genetics and Genomics, Washington University in Saint Louis, Saint Louis, MO 63130, USA;
- Graduate Program in Gastroenterology and Hepatology, Universidade Federal do Rio Grande do Sul, Porto Alegre 90610-000, Brazil
| | - Karl J. Clark
- Department of Biochemical and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
| | | | - Eric W. Klee
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA;
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN 55905, USA
- Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN 55905, USA
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Jang S, Ahn YH, Ko JM, Ko JS, Lim S, Kang HG. Case report: Focal segmental glomerulosclerosis in a pediatric atypical progeroid syndrome. Front Pediatr 2022; 10:1032653. [PMID: 36389384 PMCID: PMC9660256 DOI: 10.3389/fped.2022.1032653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/03/2022] [Indexed: 11/13/2022] Open
Abstract
Atypical progeroid syndrome (APS) is a rare type of progeroid syndrome mainly caused by heterozygous missense mutations in the LMNA (MIM 150330) gene. APS has heterogeneous clinical manifestations, and its kidney manifestations, particularly in children, are rarely documented. Here, we report the first pediatric case of APS with focal segmental glomerulosclerosis (FSGS). A 10-year-old boy with progeroid features was referred to the nephrology clinic because of hyperuricemia. He had dark skin, protruding eyes, and beaked nose and was very thin, suggesting lipodystrophy. He had been treated for recurrent urinary tract infection during infancy, and liver biopsy for persisting hepatitis showed steatohepatitis. He also had hypertrophic cardiomyopathy (HCMP) with mitral and tricuspid valve regurgitation. Genetic studies were performed considering his multisystem symptoms, and he was diagnosed as having APS according to exome sequencing findings (c.898G > C, p.Asp300His of LMNA). During the first visit to the nephrology clinic, he had minimal proteinuria (urine protein/creatinine ratio of 0.23 mg/mg), which worsened during follow-up. In three years, his urine protein/creatinine ratio and N-acetyl-b-D-glucosaminidase/creatinine ratio increased to 1.52 and 18.7, respectively. The kidney biopsy result was consistent with findings of FSGS, peri-hilar type, showing segmental sclerosis of 1 (5%) glomerulus out of 21 glomeruli. An angiotensin receptor blocker was added to manage his proteinuria. This is the first pediatric report of FSGS in an APS patient with confirmed LMNA defect, who manifested progeroid features, lipodystrophy, HCMP with heart valve dysfunction, and steatohepatitis. Our case suggests that screening for proteinuric nephropathy is essential for managing APS patients since childhood.
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Affiliation(s)
- Seoyun Jang
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, South Korea
| | - Yo Han Ahn
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, South Korea.,Department of Pediatrics, Seoul National University College of Medicine, Seoul, South Korea.,Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea
| | - Jung Min Ko
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, South Korea.,Department of Pediatrics, Seoul National University College of Medicine, Seoul, South Korea.,Rare Disease Center, Seoul National University Hospital, Seoul, South Korea
| | - Jae Sung Ko
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, South Korea
| | - Sojung Lim
- Department of Pathology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea
| | - Hee Gyung Kang
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, South Korea.,Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea.,Wide River Institute of Immunology, Seoul National University, Hongcheon, South Korea
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Coppedè F. Mutations Involved in Premature-Ageing Syndromes. APPLICATION OF CLINICAL GENETICS 2021; 14:279-295. [PMID: 34103969 PMCID: PMC8180271 DOI: 10.2147/tacg.s273525] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/17/2021] [Indexed: 12/12/2022]
Abstract
Premature-ageing syndromes are a heterogeneous group of rare genetic disorders resembling features of accelerated ageing and resulting from mutations in genes coding for proteins required for nuclear lamina architecture, DNA repair and maintenance of genome stability, mitochondrial function and other cellular processes. Hutchinson–Gilford progeria syndrome (HGPS) and Werner syndrome (WS) are two of the best-characterized progeroid syndromes referred to as childhood- and adulthood-progeria, respectively. This article provides an updated overview of the mutations leading to HGPS, WS, and to the spectrum of premature-ageing laminopathies ranging in severity from congenital restrictive dermopathy (RD) to adult-onset atypical WS, including RD-like laminopathies, typical and atypical HGPS, more and less severe forms of mandibuloacral dysplasia (MAD), Néstor-Guillermo progeria syndrome (NGPS), atypical WS, and atypical progeroid syndromes resembling features of HGPS and/or MAD but resulting from impaired DNA repair or mitochondrial functions, including mandibular hypoplasia, deafness, progeroid features, and lipodystrophy (MDPL) syndrome and mandibuloacral dysplasia associated to MTX2 (MADaM). The overlapping signs and symptoms among different premature-ageing syndromes, resulting from both a large genetic heterogeneity and shared pathological pathways underlying these conditions, require an expert clinical evaluation in specialized centers paralleled by next-generation sequencing of panels of genes involved in these disorders in order to establish as early as possible an accurate clinical and molecular diagnosis for a proper patient management.
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Affiliation(s)
- Fabio Coppedè
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy
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