Variants in Nebulin (NEB) Are Linked to the Development of Familial Primary Angle Closure Glaucoma in Basset Hounds

PLoS One. 2015 May 4;10(5):e0126660. doi: 10.1371/journal.pone.0126660. eCollection 2015.

Abstract

Several dog breeds are susceptible to developing primary angle closure glaucoma (PACG), which suggests a genetic basis for the disease. We have identified a four-generation Basset Hound pedigree with characteristic autosomal recessive PACG that closely recapitulates PACG in humans. Our aim is to utilize gene mapping and whole exome sequencing approaches to identify PACG-causing sequence variants in the Basset. Extensive clinical phenotyping of all pedigree members was conducted. SNP-chip genotyping was carried out in 9 affected and 15 unaffected pedigree members. Two-point and multipoint linkage analyses of genome-wide SNP data were performed using Superlink-Online SNP-1.1 and a locus was mapped to chromosome 19q with a maximum LOD score of 3.24. The locus contains 12 Ensemble predicted canine genes and is syntenic to a region on chromosome 2 in the human genome. Using exome-sequencing analysis, a possibly damaging, non-synonymous variant in the gene Nebulin (NEB) was found to segregate with PACG which alters a phylogenetically conserved Lysine residue. The association of this variants with PACG was confirmed in a secondary cohort of unrelated Basset Hounds (p = 3.4 × 10-4, OR = 15.3 for homozygosity). Nebulin, a protein that promotes the contractile function of sarcomeres, was found to be prominently expressed in the ciliary muscles of the anterior segment. Our findings may provide insight into the molecular mechanisms that underlie PACG. The phenotypic similarities of disease presentation in dogs and humans may enable the translation of findings made in this study to patients with PACG.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Chromosome Mapping
  • Computational Biology / methods
  • Dog Diseases / diagnosis
  • Dog Diseases / genetics*
  • Dogs
  • Exome
  • Genetic Linkage
  • Genetic Predisposition to Disease*
  • Genetic Variation*
  • Genotype
  • Glaucoma, Angle-Closure / veterinary*
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Lod Score
  • Molecular Sequence Data
  • Muscle Proteins / genetics*
  • Muscle Proteins / metabolism
  • Mutation
  • Phenotype
  • Polymorphism, Single Nucleotide
  • Sequence Alignment

Substances

  • Muscle Proteins
  • nebulin

Grants and funding

Markus Kuehn received funding for this work from the American Kennel Club – AKC Canine Health Foundation (CHF01594). Rob W.J. Collin received funding for this work from the Stichting A.F Deutman Researchfonds Oogheelknde Nijmegen and from the Landelijke Stichting voor Blinden en Slechtzienden. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.