Identification of the gene responsible for gelatinous drop-like corneal dystrophy

Nat Genet. 1999 Apr;21(4):420-3. doi: 10.1038/7759.

Abstract

Gelatinous drop-like corneal dystrophy (GDLD; OMIM 204870) is an autosomal recessive disorder characterized by severe corneal amyloidosis leading to blindness, with an incidence of 1 in 300,000 in Japan. Our previous genetic linkage study localized the gene responsible to a 2.6-cM interval on chromosome 1p. Clinical manifestations, which appear in the first decade of life, include blurred vision, photophobia and foreign-body sensation. By the third decade, raised, yellowish-grey, gelatinous masses severely impair visual acuity, and lamellar keratoplasty is required for most patients. Here we report DNA sequencing, cDNA cloning and mutational analyses of four deleterious mutations (Q118X, 632delA, Q207X and S170X) in M1S1 (formerly TROP2 and GA733-1), encoding a gastrointestinal tumour-associated antigen. The Q118X mutation was the most common alteration in the GDLD patients examined, accounting for 33 of 40 (82.5%) disease alleles in our panel of families. Protein expression analysis revealed aggregation of the mutated, truncated protein in the perinuclear region, whereas the normal protein was distributed diffusely in the cytoplasm with a homogenous or fine granular pattern. Our successful identification of the gene that is defective in GDLD should facilitate genetic diagnosis and potentially treatment of the disease, and enhance general understanding of the mechanisms of amyloidosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloidosis / genetics*
  • Animals
  • Antigens, Neoplasm / genetics*
  • Antigens, Neoplasm / metabolism
  • Binding Sites
  • COS Cells / metabolism
  • Cell Adhesion Molecules / genetics*
  • Cell Adhesion Molecules / metabolism
  • Cloning, Molecular
  • Corneal Dystrophies, Hereditary / genetics*
  • Epithelial Cell Adhesion Molecule
  • Female
  • Genetic Markers
  • HeLa Cells / metabolism
  • Homozygote
  • Humans
  • Japan
  • Linkage Disequilibrium
  • Male
  • Molecular Sequence Data
  • Mutation*
  • Phosphatidylinositol 4,5-Diphosphate / metabolism
  • Polymerase Chain Reaction
  • Polymorphism, Restriction Fragment Length
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Analysis

Substances

  • Antigens, Neoplasm
  • Cell Adhesion Molecules
  • Epithelial Cell Adhesion Molecule
  • Genetic Markers
  • Phosphatidylinositol 4,5-Diphosphate
  • Recombinant Proteins

Associated data

  • GENBANK/P06396
  • GENBANK/U33055
  • GENBANK/X13425
  • GENBANK/X77753
  • GENBANK/Y08830