Variants in KIAA0825 underlie autosomal recessive postaxial polydactyly

  • Hum Genet. 2019 Jun;138(6):593-600. doi: 10.1007/s00439-019-02000-0.
Irfan Ullah  #  1 Naseebullah Kakar  #  2  3 Isabelle Schrauwen  #  4 Shabir Hussain  #  1  4 Imen Chakchouk  4 Khurram Liaqat  4  5 Anushree Acharya  4 Naveed Wasif  2  6 Regie Lyn P Santos-Cortez  4 Saadullah Khan  7 Abdul Aziz  1  8 Kwanghyuk Lee  4 Julien Couthouis  9 Denise Horn  10 Bjørt K Kragesteen  10 Malte Spielmann  10 Holger Thiele  11 Deborah A Nickerson  12 Michael J Bamshad  12  13 Aaron D Gitler  9 Jamil Ahmad  3 Muhammad Ansar  1 Guntram Borck  2 Wasim Ahmad  1 Suzanne M Leal  14
Affiliations
  • 1. Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
  • 2. Institute of Human Genetics, University of Ulm, Ulm, Germany.
  • 3. Department of Biotechnology, Balochistan University of Information Technology, Engineering, and Management Sciences, Quetta, Pakistan.
  • 4. Department of Molecular and Human Genetics, Center for Statistical Genetics, Baylor College of Medicine, 1 Baylor Plaza 700D, Houston, TX, 77030, USA.
  • 5. Department of Biotechnology, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad, Islamabad, Pakistan.
  • 6. Institute of Molecular Biology and Biotechnology (IMBB), The University of Lahore, Lahore, Pakistan.
  • 7. Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Pakistan.
  • 8. Department of Computer Science and Bioinformatics, Khushal Khan Khattak University, Karak, Pakistan.
  • 9. Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
  • 10. Institute for Medical Genetics and Human Genetics, Charité Universitätsmedizin Berlin, Berlin, Germany.
  • 11. Cologne Center for Genomics (CCG), Universitat zu Koln, Cologne, Germany.
  • 12. Department of Genome Sciences, University of Washington, Seattle, USA.
  • 13. Department of Pediatrics, University of Washington, Seattle, WA, USA.
  • 14. Department of Molecular and Human Genetics, Center for Statistical Genetics, Baylor College of Medicine, 1 Baylor Plaza 700D, Houston, TX, 77030, USA. [email protected].
  • # Contributed equally.
Abstract

Postaxial polydactyly (PAP) is a common limb malformation that often leads to cosmetic and functional complications. Molecular evaluation of polydactyly can serve as a tool to elucidate genetic and signaling pathways that regulate limb development, specifically, the anterior-posterior specification of the limb. To date, only five genes have been identified for nonsyndromic PAP: FAM92A, GLI1, GLI3, IQCE and ZNF141. In this study, two Pakistani multiplex consanguineous families with autosomal recessive nonsyndromic PAP were clinically and molecularly evaluated. From both pedigrees, a DNA sample from an affected member underwent exome Sequencing. In each family, we identified a segregating frameshift (c.591dupA [p.(Q198Tfs*21)]) and nonsense variant (c.2173A > T [p.(K725*)]) in KIAA0825 (also known as C5orf36). Although KIAA0825 encodes a protein of unknown function, it has been demonstrated that its murine ortholog is expressed during limb development. Our data contribute to the establishment of a catalog of genes important in limb patterning, which can aid in diagnosis and obtaining a better understanding of the biology of polydactyly.