Diagnostic testing for primary congenital glaucoma. Carrier screening for primary congenital glaucoma.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Characteristics: High intraocular pressure, globe enlargement and edema, corneal opacification, thinning of anterior sclera, iris atrophy, anomalous deep anterior chamber, photophobia, blepharospasm, and excessive tearing.
Incidence: 1:5,000-20,000 individuals in Western countries; varies in other ethnicities.
Inheritance: Autosomal recessive.
Cause: Two Cytochrome P4501B1 (CYP1B1) gene mutations.
Clinical Sensitivity: 20-100% in familial cases, 10-15% in isolated cases.
Methodology: Bidirectional sequencing of the entire CYP1B1 coding region, intron-exon boundaries and 5 prime untranslated region.
Analytical Sensitivity and Specificity: 99%
Limitations: Large gene deletions/duplications and deep intronic mutations will not be detected. Diagnostic errors can occur due to rare sequence variations.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
|0051475||Primary Congenital Glaucoma, Sequencing|
- CYP1B1 sequencing