Primary Congenital Glaucoma - Glaucoma

  • Diagnosis
  • Background
  • Lab Tests
  • References
  • Related Topics

Indications for Testing

  • Cornea clouding in infant or child
  • Carrier screening for family members
    • Of children with persistent redeye
    • When a causative CYP1B1 mutation is identified
  • Prenatal testing for at-risk pregnancies in families where the causative CYP1B1 mutations are known

Laboratory Testing

  • CYP1B1 gene sequencing
    • Gene occurrence in congenital glaucoma
      • Familial – 20-100%
      • Nonfamilial – 10-15%
    • Absence of mutations does not necessarily rule out carrier status or the presence of disease

Differential Diagnosis

  • Corneal edema or opacity
  • Corneal enlargement
    • Axial myopia
    • Hereditary megalocornea
    • Keratoglobus
  • Epiphora and red eye
    • Conjunctivitis
    • Corneal abrasion
    • Uveitis
    • Keratitis
  • Photophobia

Glaucoma is the second leading cause of blindness in the world and the leading cause of blindness among African Americans. Primary congenital glaucoma (PCG) is the most common childhood glaucoma. A notable subtype, newborn PCG, may often have the most severe and clinically challenging expression. Mutations in the CYP1B1 gene are responsible for >50% of cases in some populations.


  • Birth prevalence
    • 1/10,000 in Western developed countries
    • 1/2,500 in Middle Eastern countries
    • 1/1,250 in Slovakian Romani populations
    • 1/3,300 in Andhra Pradesh state of India
  • Age – infancy
  • Sex
    • M>F, 3:1 in U.S.
    • M<F, 2:3 in Japan


  • Autosomal recessive inheritance of mutations in the CYP1B1 gene
    • Homozygosity – predictive of disease
    • Heterozygosity – carrier status; carriers are unaffected


  • Abnormality of trabecular meshwork creates an abnormal filtration angle
  • Abnormal angle creates resistance to ocular aqueous outflow
    • Results in increased intraocular pressure

Clinical Presentation

  • Ocular symptoms vary in severity – bilateral 70% of the time
  • Symptoms
    • Photophobia
    • Epiphora
    • Blepharospasm
    • Chronic red or irritated eyes, excessive tearing
    • Reduced visual acuity – eventual blindness
  • Signs
    • Globe enlargement/edema
    • Iris and pupillary abnormalities
    • Optic nerve cupping
    • Myopia
    • Corneal opacification
    • Elevated intraocular pressure
    • Thinning of anterior sclera, anomalous deep anterior chamber
Tests generally appear in the order most useful for common clinical situations. Click on number for test-specific information in the ARUP Laboratory Test Directory.

Glaucoma (Primary Congenital), CYP1B1 Sequencing 0051476
Method: Polymerase Chain Reaction/Sequencing


Large gene deletions/duplications and deep intronic mutations will not be detected

Diagnostic errors can occur due to rare sequence variations

General References

Abu-Amero K, Edward D. Primary Congenital Glaucoma. In: Pagon RA, Adam MP, Ardinger HH, et al, editors. GeneReviews, University of Washington, 1993-2015. Seattle, WA [Last updated Mar 2014; Accessed: Nov 2015]

Challa P. Genetics of adult glaucoma. Int Ophthalmol Clin. 2011; 51(3): 37-51. PubMed

Girgis N, Chen TC. Genetics of the pediatric glaucomas. Int Ophthalmol Clin. 2011; 51(3): 107-17. PubMed

Vasiliou V, Gonzalez FJ. Role of CYP1B1 in glaucoma. Annu Rev Pharmacol Toxicol. 2008; 48: 333-58. PubMed

References from the ARUP Institute for Clinical and Experimental Pathology®

Damjanovich K, Baldwin EE, Lewis T, Bayrak-Toydemir P. Novel homozygous CYP1B1 deletion in siblings with primary congenital glaucoma. Ophthalmic Genet. 2013; 34(3): 180-1. PubMed

Medical Reviewers

Last Update: July 2017