2. Academic Validation
  3. Biallelic Mutations in TMTC3, Encoding a Transmembrane and TPR-Containing Protein, Lead to Cobblestone Lissencephaly

Biallelic Mutations in TMTC3, Encoding a Transmembrane and TPR-Containing Protein, Lead to Cobblestone Lissencephaly

  • Am J Hum Genet. 2016 Nov 3;99(5):1181-1189. doi: 10.1016/j.ajhg.2016.09.007.
Julie Jerber 1,  Maha S Zaki 2,  Jumana Y Al-Aama 3,  Rasim Ozgur Rosti 1,  Tawfeg Ben-Omran 4,  Esra Dikoglu 1,  Jennifer L Silhavy 1,  Caner Caglar 5,  Damir Musaev 1,  Beate Albrecht 6,  Kevin P Campbell 7,  Tobias Willer 7,  Mariam Almuriekhi 4,  Ahmet Okay Çağlayan 8,  Jiri Vajsar 9,  Kaya Bilgüvar 10,  Gonul Ogur 11,  Rami Abou Jamra 12,  Murat Günel 10,  Joseph G Gleeson 13
Affiliations

Affiliations

  • 1 Laboratory for Pediatric Brain Disease, The Rockefeller University, New York, NY 10065, USA; Howard Hughes Medical Institute, Rady Children's Institute for Genomic Medicine, University of California, San Diego, San Diego, CA 92093, USA.
  • 2 Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo 12311, Egypt.
  • 3 Princess Al-Jawhara Al-Brahim Center of Excellence in Research of Hereditary Disorders, King Abdulaziz University, Jeddah 21453, Saudi Arabia; Department of Genetic Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah 21453, Saudi Arabia.
  • 4 Clinical and Metabolic Genetics Section, Department of Pediatrics, Hamad Medical Corporation, PO Box 3050, Doha, Qatar; Weill Cornell Medical College, Qatar, Education City, PO Box 24144, Doha, Qatar.
  • 5 Laboratory for Pediatric Brain Disease, The Rockefeller University, New York, NY 10065, USA.
  • 6 Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, 45122 Essen, Germany.
  • 7 Howard Hughes Medical Institute, Departments of Neurology, Internal Medicine, and Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1101, USA.
  • 8 Department of Medical Genetics, School of Medicine, Istanbul Bilim University, Istanbul 34394, Turkey.
  • 9 Division of Neurology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.
  • 10 Yale Program on Neurogenetics, Departments of Neurosurgery, Neurobiology, and Genetics, School of Medicine, Yale University, New Haven, CT 06510, USA.
  • 11 Department of Genetics, School of Medicine, Ondokuz Mayis University, 55000 Samsun, Turkey.
  • 12 Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Philipp-Rosenthal-Str. 55, 04103 Leipzig, Germany; Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany.
  • 13 Laboratory for Pediatric Brain Disease, The Rockefeller University, New York, NY 10065, USA; Howard Hughes Medical Institute, Rady Children's Institute for Genomic Medicine, University of California, San Diego, San Diego, CA 92093, USA. Electronic address: jogleeson@mail.rockefeller.edu.
PMID: 27773428 DOI: 10.1016/j.ajhg.2016.09.007
Abstract

Cobblestone lissencephaly (COB) is a severe brain malformation in which overmigration of neurons and glial cells into the arachnoid space results in the formation of cortical dysplasia. COB occurs in a wide range of genetic disorders known as dystroglycanopathies, which are congenital muscular dystrophies associated with brain and eye anomalies and range from Walker-Warburg syndrome to Fukuyama congenital muscular dystrophy. Each of these conditions has been associated with alpha-dystroglycan defects or with mutations in genes encoding basement membrane components, which are known to interact with alpha-dystroglycan. Our screening of a cohort of 25 families with recessive forms of COB identified six families affected by biallelic mutations in TMTC3 (encoding transmembrane and tetratricopeptide repeat containing 3), a gene without obvious functional connections to alpha-dystroglycan. Most affected individuals showed brainstem and cerebellum hypoplasia, as well as ventriculomegaly. However, the minority of the affected individuals had eye defects or elevated muscle creatine phosphokinase, separating the TMTC3 COB phenotype from typical congenital muscular dystrophies. Our data suggest that loss of TMTC3 causes COB with minimal eye or muscle involvement.

Keywords

TMTC3; alpha-dystroglycan; cobblestone lissencephaly; endoplasmic reticulum.

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