Preferred genetic test for individuals of high-risk ethnic backgrounds other than those of African descent. For initial screening for GP6D deficiency, refer to Glucose-6-Phosphate Dehydrogenase (0080135).
- 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:G6PD deficiency can cause chronic hemolytic anemia, food-, drug-and infection-mediated hemolytic anemia, and acute hemolytic anemia with jaundice in the newborn-which can be potentially life-threatening. Ethnic-specific variants are common in individuals of African, Southeast Asian and Mediterranean descent. Most mutations identified to-date have been classified according to the following scheme: Class I-severe enzyme deficiency with chronic non-spherocytic hemolytic anemia (CNSHA); Class II-severe enzyme deficiency with less than 10 percent of the normal activity; Class III-mild to moderate enzyme deficiency (10 to 60 percent of normal activity); and Class IV-very mild to almost normal enzyme activity (greater than 60 percent normal activity with no clinical consequences).
Incidence: Varies by ethnicity. 7 in 10 Kurdish Jewish males; 1 in 6 to 10 African American males; 1 in 7 to 9 Arabic males; 1 in 6 to 16 Southeast Asian males.
Inheritance: X-linked recessive.
Penetrance: Variable depending on mutation and sex.
Cause:Pathogenic mutations in Glucose-6-Phosphate Dehydrogenase (G6PD) gene.
Clinical Sensitivity: Expected greater than 98 percent.
Methodology: Bidirectional sequencing of the entire G6PD coding region and intron-exon boundaries.
Analytical Sensitivity and Specificity: 99 percent.
Limitations:Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations, deep intronic mutations, and large deletions/duplications will not be detected. Mutations in genes other than G6PD are not evaluated.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
|2007164||G6PD Deficiency (G6PD) Seq Specimen|
|2007165||G6PD Deficiency (G6PD) Seq Interp|
- G-6-PD Deficiency (G6PD) Sequencing
- G6PD Sequencing
- Hemolytic Anemia (G6PD) Sequencing
- Hyperbilirubinemia (G6PD) Sequencing
- RBC G6PD sequencing