Molecular and clinical evaluation of a patient hemizygous for TIGR/MYOC

Arch Ophthalmol. 2001 Nov;119(11):1674-8. doi: 10.1001/archopht.119.11.1674.


Objective: To determine if a patient with an interstitial deletion of chromosome 1 is hemizygous for the TIGR/MYOC gene and if that patient has glaucoma.

Methods: A patient with an interstitial deletion of chromosome 1 was clinically examined for evidence of glaucoma. DNA samples from the patient and her family were used for molecular studies to determine the boundaries of the chromosome 1 deletion using polymorphic markers located on chromosome 1q21 to 1q24. Additional markers located in the vicinity of the TIGR/MYOC gene, including 2 derived from the ends of the gene, were used to determine if it was included in the deletion.

Results: The patient and her family showed no evidence of glaucoma. Molecular analysis demonstrated that a complex deletion of the maternal copy of chromosome 1 included the entire TIGR/MYOC gene.

Conclusions: We have determined that the patient has only 1 functional copy of TIGR/MYOC. The lack of clinical evidence of glaucoma suggests that haploinsufficiency of the TIGR/MYOC protein is not the cause of early-onset glaucoma associated with mutations in TIGR/MYOC.

Clinical relevance: Missense and nonsense mutations in the TIGR/MYOC gene have been associated with juvenile- and adult-onset primary open-angle glaucoma. Although many different mutations have been correlated with the disease, the underlying genetic mechanism (haploinsufficiency, gain of function, or a dominant negative effect) remains unknown. Information regarding the genetic mechanism responsible for TIGR/MYOC-associated glaucoma is necessary for further studies designed to develop transgenic animal models and gene-related therapy.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Chromosome Deletion*
  • Chromosomes, Human, Pair 1 / genetics*
  • Cytoskeletal Proteins
  • DNA Mutational Analysis
  • Eye Proteins / genetics*
  • Female
  • Glaucoma, Open-Angle / diagnosis
  • Glaucoma, Open-Angle / genetics*
  • Glycoproteins / genetics*
  • Humans
  • Intraocular Pressure
  • Microsatellite Repeats
  • Mutation, Missense
  • Pedigree


  • Cytoskeletal Proteins
  • Eye Proteins
  • Glycoproteins
  • trabecular meshwork-induced glucocorticoid response protein