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Bakar A, Shams S, Bibi N, Ullah A, Ahmad W, Jelani M, Muthaffar OY, Abdulkareem AA, Abujamel TS, Haque A, Naseer MI, Khan B. A Novel Homozygous Nonsense Variant in the DYM Underlies Dyggve-Melchior-Clausen Syndrome in Large Consanguineous Family. Genes (Basel) 2023; 14:510. [PMID: 36833437 PMCID: PMC9956627 DOI: 10.3390/genes14020510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/09/2023] [Accepted: 02/15/2023] [Indexed: 02/19/2023] Open
Abstract
(1) Background: Dyggve-Melchior-Clausen Syndrome is a skeletal dysplasia caused by a defect in the DYM gene (OMIM number 607461). Pathogenic variants in the gene have been reported to cause Dyggve-Melchior-Clausen (DMC; OMIM 223800) dysplasia and Smith-McCort (SMC; OMIM 607326) dysplasia. (2) Methods: In the present study, large consanguineous families with five affected individuals with osteochondrodysplasia phenotypes were recruited. The family members were analyzed by polymerase chain reaction for homozygosity mapping using highly polymorphic microsatellite markers. Subsequent to linkage analysis, the coding exons and exon intron border of the DYM gene were amplified. The amplified products were then sent for Sanger sequencing. The structural effect of the pathogenic variant was analyzed by different bioinformatics tools. (3) Results: Homozygosity mapping revealed a 9 Mb homozygous region on chromosome 18q21.1 harboring DYM shared by all available affected individuals. Sanger sequencing of the coding exons and exon intron borders of the DYM gene revealed a novel homozygous nonsense variant [DYM (NM_017653.6):c.1205T>A, p.(Leu402Ter)] in affected individuals. All the available unaffected individuals were either heterozygous or wild type for the identified variant. The identified mutation results in loss of protein stability and weekend interactions with other proteins making them pathogenic (4) Conclusions: This is the second nonsense mutation reported in a Pakistani population causing DMC. The study presented would be helpful in prenatal screening, genetic counseling, and carrier testing of other members in the Pakistani community.
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Affiliation(s)
- Abu Bakar
- Department of Biochemistry, Abdul Wali Khan University Mardan, Mardan 23200, Pakistan
| | - Sulaiman Shams
- Department of Biochemistry, Abdul Wali Khan University Mardan, Mardan 23200, Pakistan
| | - Nousheen Bibi
- Department of Bioinformatics, Shaheed Benazir Bhutto Women University, Peshawar 25120, Pakistan
| | - Asmat Ullah
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
- Department of Biochemistry, Quaid-I-Azam University, Islamabad 45320, Pakistan
| | - Wasim Ahmad
- Department of Biochemistry, Quaid-I-Azam University, Islamabad 45320, Pakistan
| | - Musharraf Jelani
- Rare Diseases Genetics and Genomics, Centre for Omic Sciences, Islamia College Peshawar, Peshawar 25120, Pakistan
| | - Osama Yousef Muthaffar
- Department of Pediatrics, Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Angham Abdulrhman Abdulkareem
- Faculty of Science, Department of Biochemistry, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Turki S. Abujamel
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Vaccines and Immunotherapy Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Absarul Haque
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21859, Saudi Arabia
| | - Muhammad Imran Naseer
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Bushra Khan
- Department of Biochemistry, Abdul Wali Khan University Mardan, Mardan 23200, Pakistan
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Tüysüz B, Geyik F, Yıldırım T, Alkaya DU, Sharifova S, Kafadar A. Seven patients with Smith-McCort dysplasia 2: Four novel nonsense variants in RAB33B and follow-up findings. Eur J Med Genet 2021; 64:104248. [PMID: 34000439 DOI: 10.1016/j.ejmg.2021.104248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 05/10/2021] [Accepted: 05/10/2021] [Indexed: 12/15/2022]
Abstract
Smith-McCort dysplasia 2 (SMC2) is a rare spondylo-epiphyseal-metaphyseal dysplasia caused by biallelic RAB33B variants. Short trunk dwarfism and radiological findings including the lacy ilia appearance and double bumps of the vertebral bodies are typical features. To date, only eight patients with SMC2 had been reported. The aim of this study is to evaluate the follow-up findings of seven patients from five families with SMC2 and to present four novel variants in RAB33B. The age of diagnosis of the patients was between 4 and 18 years. All patients had variable degrees of short trunk dwarfism with barrel chest, waddling gait, hyperlordosis, genu valgum, elbow and finger joint stiffness, which became more evident with growth. Lacy iliac crest, short ilia with basilar hypoplasia, platyspondyly, dysplastic acetabulum with small and/or laterally displaced femoral heads, and small, irregular carpal bones were detected on skeletal radiographies of all patients. Typical double hump appearance of vertebral bodies was present in patients under 12 years of age, which disappeared after puberty and development of elongated vertebral bodies was also observed. At the time of diagnosis, six patients were able to walk independently; patients who were followed for five to nine years, developed severe hip pain, hip and knee joints stiffness and difficultly of walking after 10 years of age. Only two patients could walk independently during final examination. We detected four novel nonsense variants (p.Gln85Ter, p. Cys48Ter, p. Arg94Ter and p. Gln134Ter) in RAB33B. This study provides important data on long-term skeletal findings of the patients with SMC2.
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Affiliation(s)
- Beyhan Tüysüz
- Department of Pediatric Genetics, Istanbul University-Cerrahpaşa, Cerrahpaşa Medical Faculty, Istanbul, Turkey.
| | - Filiz Geyik
- Department of Pediatric Genetics, Istanbul University-Cerrahpaşa, Cerrahpaşa Medical Faculty, Istanbul, Turkey
| | - Timur Yıldırım
- Department of Orthopedics and Traumatology, University of Health Sciences Turkey, Baltalimani Bone Diseases Training and Research Center, Istanbul, Turkey
| | - Dilek Uludağ Alkaya
- Department of Pediatric Genetics, Istanbul University-Cerrahpaşa, Cerrahpaşa Medical Faculty, Istanbul, Turkey
| | - Sabine Sharifova
- Department of Pediatric Genetics, Istanbul University-Cerrahpaşa, Cerrahpaşa Medical Faculty, Istanbul, Turkey
| | - Ali Kafadar
- Department of Neurosurgery, Istanbul University-Cerrahpaşa, Cerrahpaşa Medical Faculty, Istanbul, Turkey
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Salian S, Cho TJ, Phadke SR, Gowrishankar K, Bhavani GS, Shukla A, Jagadeesh S, Kim OH, Nishimura G, Girisha KM. Additional three patients with Smith-McCort dysplasia due to novel RAB33B mutations. Am J Med Genet A 2017; 173:588-595. [PMID: 28127940 DOI: 10.1002/ajmg.a.38064] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 11/14/2016] [Indexed: 11/06/2022]
Abstract
Smith-McCort dysplasia (SMC OMIM 615222) and Dyggve-Melchior-Clausen dysplasia (DMC OMIM 223800) are allelic skeletal dysplasias caused by homozygous or compound heterozygous mutations in DYM (OMIM 607461). Both disorders share the same skeletal phenotypes characterized by spondylo-epi-metaphyseal dysplasia with distinctive lacy ilia. The difference rests on the presence or absence of intellectual disability, that is, intellectual disability in DMC and normal cognition in SMC. However, genetic heterogeneity was suspected in SMC. Recently, RAB33B (OMIM 605950) has been identified as the second gene for SMC. Nevertheless, only two affected families have been reported so far. Here we present three SMC patients with four novel pathogenic variants in RAB33B, including homozygosity for c.211C>T (p.R71*), homozygosity for c.365T>C (p.F122S), and compound heterozygosity for c.48delCGGGGCAG (p.G17Vfs*58) and c.490C>T (p.Q164*). We also summarize the clinical, radiological, and mutation profile of RAB33B after literature mining. This report ascertains the pathogenic relationship between RAB33B and SMC. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Smrithi Salian
- Department of Medical Genetics, Kasturba Medical College, Manipal University, Manipal, India
| | - Tae-Joon Cho
- Division of Pediatric Orthopedics, Seoul National University Children's Hospital, Seoul, Korea
| | - Shubha R Phadke
- Department of Medical Genetics, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Kalpana Gowrishankar
- Department of Medical Genetics, Apollo Children's Hospital, Chennai, Tamilnadu, India
| | | | - Anju Shukla
- Department of Medical Genetics, Kasturba Medical College, Manipal University, Manipal, India
| | | | - Ok-Hwa Kim
- Department of Radiology, Woorisoa Children's Hospital, Seoul, Korea
| | - Gen Nishimura
- Department of Pediatric Imaging, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | - Katta M Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal University, Manipal, India
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Dupuis N, Fafouri A, Bayot A, Kumar M, Lecharpentier T, Ball G, Edwards D, Bernard V, Dournaud P, Drunat S, Vermelle-Andrzejewski M, Vilain C, Abramowicz M, Désir J, Bonaventure J, Gareil N, Boncompain G, Csaba Z, Perez F, Passemard S, Gressens P, El Ghouzzi V. Dymeclin deficiency causes postnatal microcephaly, hypomyelination and reticulum-to-Golgi trafficking defects in mice and humans. Hum Mol Genet 2015; 24:2771-83. [PMID: 25652408 DOI: 10.1093/hmg/ddv038] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 01/31/2015] [Indexed: 01/02/2023] Open
Abstract
Dymeclin is a Golgi-associated protein whose deficiency causes Dyggve-Melchior-Clausen syndrome (DMC, MIM #223800), a rare recessively inherited spondyloepimetaphyseal dysplasia consistently associated with postnatal microcephaly and intellectual disability. While the skeletal phenotype of DMC patients has been extensively described, very little is known about their cerebral anomalies, which result in brain growth defects and cognitive dysfunction. We used Dymeclin-deficient mice to determine the cause of microcephaly and to identify defective mechanisms at the cellular level. Brain weight and volume were reduced in all mutant mice from postnatal day 5 onward. Mutant mice displayed a narrowing of the frontal cortex, although cortical layers were normally organized. Interestingly, the corpus callosum was markedly thinner, a characteristic we also identified in DMC patients. Consistent with this, the myelin sheath was thinner, less compact and not properly rolled, while the number of mature oligodendrocytes and their ability to produce myelin basic protein were significantly decreased. Finally, cortical neurons from mutant mice and primary fibroblasts from DMC patients displayed substantially delayed endoplasmic reticulum to Golgi trafficking, which could be fully rescued upon Dymeclin re-expression. These findings indicate that Dymeclin is crucial for proper myelination and anterograde neuronal trafficking, two processes that are highly active during postnatal brain maturation.
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Affiliation(s)
- Nina Dupuis
- Inserm, U1141, Paris, France, Sorbonne Paris Cité, Univ Paris Diderot, UMRS 1141, Paris, France
| | - Assia Fafouri
- Inserm, U1141, Paris, France, Sorbonne Paris Cité, Univ Paris Diderot, UMRS 1141, Paris, France
| | - Aurélien Bayot
- Inserm, U1141, Paris, France, Sorbonne Paris Cité, Univ Paris Diderot, UMRS 1141, Paris, France
| | - Manoj Kumar
- Inserm, U1141, Paris, France, Sorbonne Paris Cité, Univ Paris Diderot, UMRS 1141, Paris, France
| | - Tifenn Lecharpentier
- Inserm, U1141, Paris, France, Sorbonne Paris Cité, Univ Paris Diderot, UMRS 1141, Paris, France
| | - Gareth Ball
- Centre for the Developing Brain, Department of Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, UK
| | - David Edwards
- Centre for the Developing Brain, Department of Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, UK
| | - Véronique Bernard
- CNRS UMR7224, Inserm, U952, Paris, France, Univ Pierre et Marie Curie, Paris, France
| | - Pascal Dournaud
- Inserm, U1141, Paris, France, Sorbonne Paris Cité, Univ Paris Diderot, UMRS 1141, Paris, France
| | - Séverine Drunat
- Inserm, U1141, Paris, France, Sorbonne Paris Cité, Univ Paris Diderot, UMRS 1141, Paris, France, Service de Génétique Clinique, AP-HP, Hôpital Robert Debré, Paris, France
| | | | - Catheline Vilain
- Medical Genetics Department, Hôpital Erasme, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Marc Abramowicz
- Medical Genetics Department, Hôpital Erasme, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Julie Désir
- Medical Genetics Department, Hôpital Erasme, Université Libre de Bruxelles (ULB), Brussels, Belgium, Institut de Pathologie et de Génétique, Gosselies, Belgium
| | - Jacky Bonaventure
- CNRS UMR3347, Orsay, France, Institut Curie, Centre de Recherche, Paris, France
| | - Nelly Gareil
- CNRS UMR144, Paris, France and Institut Curie, Centre de Recherche, Paris, France
| | - Gaelle Boncompain
- CNRS UMR144, Paris, France and Institut Curie, Centre de Recherche, Paris, France
| | - Zsolt Csaba
- Inserm, U1141, Paris, France, Sorbonne Paris Cité, Univ Paris Diderot, UMRS 1141, Paris, France
| | - Franck Perez
- CNRS UMR144, Paris, France and Institut Curie, Centre de Recherche, Paris, France
| | - Sandrine Passemard
- Inserm, U1141, Paris, France, Sorbonne Paris Cité, Univ Paris Diderot, UMRS 1141, Paris, France, Service de Génétique Clinique, AP-HP, Hôpital Robert Debré, Paris, France
| | - Pierre Gressens
- Inserm, U1141, Paris, France, Sorbonne Paris Cité, Univ Paris Diderot, UMRS 1141, Paris, France, Centre for the Developing Brain, Department of Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, UK
| | - Vincent El Ghouzzi
- Inserm, U1141, Paris, France, Sorbonne Paris Cité, Univ Paris Diderot, UMRS 1141, Paris, France,
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