- 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 of chronic granulomatous disease (CGD):
A primary immunodeficiency disorder characterized by recurrent, severe bacterial and fungal infections of the skin, lymph nodes, liver, lungs, bones, or visceral organs. Dysregulated inflammatory responses result in granulomas.
Incidence: Approximately 1 in 250,000 births.
Inheritance: Autosomal recessive.
Cause: Autosomal recessive CGD may result from mutations in NCF1 (25 percent), CYBA (<5 percent), NCF2 (<5 percent) and NCF4 (very rare). Pathogenic mutations in the CYBB gene result in X-linked CGD that accounts for 60-70 percent of all CGD.
Clinical Sensitivity: 18 percent for CGD.
Methodology: Polymerase Chain Reaction/High Resolution Melt Analysis
Analytical Sensitivity: 99 percent for homozygous GT deletion, 90 percent for heterozygous GT deletion.
Analytical Specificity: 99 percent.
Limitations: Mutations other than the NCF1 exon 2 GT deletion are not evaluated. Diagnostic errors can occur due to rare sequence variations. Because of potential recombination between NCF1 and its pseudogenes, the lack of detection of the GT deletion in exon 2 does not rule out carrier status for autosomal recessive CGD.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
|2006368||NCF1 for Chronic Granalomatous Disease|
- CYBB x-linked Exon 2 deletion