2. Academic Validation
  3. Homozygous loss of DIAPH1 is a novel cause of microcephaly in humans

Homozygous loss of DIAPH1 is a novel cause of microcephaly in humans

  • Eur J Hum Genet. 2015 Feb;23(2):165-72. doi: 10.1038/ejhg.2014.82.
A Gulhan Ercan-Sencicek 1,  Samira Jambi 2,  Daniel Franjic 3,  Sayoko Nishimura 1,  Mingfeng Li 3,  Paul El-Fishawy 4,  Thomas M Morgan 5,  Stephan J Sanders 6,  Kaya Bilguvar 7,  Mohnish Suri 8,  Michele H Johnson 9,  Abha R Gupta 10,  Zafer Yuksel 11,  Shrikant Mane 12,  Elena Grigorenko 13,  Marina Picciotto 14,  Arthur S Alberts 15,  Murat Gunel 16,  Nenad Šestan 3,  Matthew W State 6
Affiliations

Affiliations

  • 1 1] Child Study Center, Yale University School of Medicine, New Haven, CT, USA [2] Department of Neurosurgery, Program on Neurogenetics, Yale School of Medicine, New Haven, CT, USA.
  • 2 Al Hada Armed Hospitals, Taif, Saudi Arabia.
  • 3 Department of Neurobiology and Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT, USA.
  • 4 Child Study Center, Yale University School of Medicine, New Haven, CT, USA.
  • 5 Department of Pediatrics, Vanderbilt University, Nashville, TN, USA.
  • 6 Department of Psychiatry, University of California, School of Medicine, San Francisco, CA, USA.
  • 7 1] Department of Neurosurgery, Program on Neurogenetics, Yale School of Medicine, New Haven, CT, USA [2] Yale Center for Mendelian Genomics, New Haven, CT, USA.
  • 8 Nottingham Clinical Genetics Service, Nottingham University Hospitals NHS, Trust City Hospital Campus, Nottingham, UK.
  • 9 Departments of Diagnostic Radiology, Surgery and Neurosurgery, Yale University School of Medicine, New Haven, CT, USA.
  • 10 1] Child Study Center, Yale University School of Medicine, New Haven, CT, USA [2] Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA.
  • 11 Department of Medical Genetics, Osmangazi University, School of Medicine, Eskisehir, Turkey.
  • 12 1] Yale Center for Mendelian Genomics, New Haven, CT, USA [2] Department of Genetics, Yale University School of Medicine, New Haven, CT, USA.
  • 13 1] Child Study Center, Yale University School of Medicine, New Haven, CT, USA [2] Moscow State University for Psychology and Education, Moscow, Russia.
  • 14 1] Child Study Center, Yale University School of Medicine, New Haven, CT, USA [2] Department of Neurobiology and Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT, USA [3] Departments of Psychiatry, Pharmocology Yale University School of Medicine, New Haven, CT, USA.
  • 15 Laboratory of Cell Structure and Signal Integration, Van Andel Research Institute, Grand Rapids, MI, USA.
  • 16 Department of Neurosurgery, Program on Neurogenetics, Yale School of Medicine, New Haven, CT, USA.
PMID: 24781755 DOI: 10.1038/ejhg.2014.82
Abstract

The combination of family-based linkage analysis with high-throughput Sequencing is a powerful approach to identifying rare genetic variants that contribute to genetically heterogeneous syndromes. Using parametric multipoint linkage analysis and whole exome Sequencing, we have identified a gene responsible for microcephaly (MCP), severe visual impairment, intellectual disability, and short stature through the mapping of a homozygous nonsense alteration in a multiply-affected consanguineous family. This gene, DIAPH1, encodes the mammalian Diaphanous-related formin (mDia1), a member of the diaphanous-related formin family of Rho effector proteins. Upon the activation of GTP-bound Rho, mDia1 generates linear actin filaments in the maintenance of polarity during adhesion, migration, and division in immune cells and neuroepithelial cells, and in driving tangential migration of cortical interneurons in the rodent. Here, we show that patients with a homozygous nonsense DIAPH1 alteration (p.Gln778*) have MCP as well as reduced height and weight. diap1 (mDia1 knockout (KO))-deficient mice have grossly normal body and brain size. However, our histological analysis of diap1 KO mouse coronal brain sections at early and postnatal stages shows unilateral ventricular enlargement, indicating that this mutant mouse shows both important similarities as well as differences with human pathology. We also found that mDia1 protein is expressed in human neuronal precursor cells during mitotic cell division and has a major impact in the regulation of spindle formation and cell division.

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