Test ID: G6PDB    
Glucose-6-Phosphate Dehydrogenase (G6PD) Full Gene Sequencing, Varies

Genetic test for individuals at high risk for glucose-6-phosphate dehydrogenase (G6PD) deficiency

Aiding in the diagnosis of G6PD deficiency

Determining G6PD deficiency status in individuals with inconclusive or unexpected phenotyping results

Differentiation of heterozygous females with skewed X-inactivation from homozygous and compound heterozygous females

Definitive diagnosis of carrier status in females

Evaluation of neonates (particularly males) with unexplained jaundice

Identifying individuals at risk of drug-induced acute hemolytic anemia (AHA) related to G6PD deficiency

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a very common X-linked condition, impacting about 400 million people worldwide. Both males and females may be impacted due to how common G6PD deficiency is in the population.

Several medications, including rasburicase, methylene blue and dapsone, result in acute hemolytic anemia (AHA) when taken by individuals with G6PD deficiency.

FDA labeling and Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines recommend that G6PD testing be undertaken in high-risk populations before prescribing drugs known to cause AHA. Knowing a patient's genotype is generally sufficient to avoid contraindicated drugs, but follow-up with the phenotyping enzyme assay may be necessary to clarify results in some cases.

This test involves full gene sequencing of all exons and intron/exon boundaries of the G6PD gene. A comprehensive interpretation will be provided including congenital and pharmacogenomic implications of results. Testing should be considered before prescribing medication associated with hemolysis in individuals with G6PD deficiency.

The following algorithms are available in Special Instructions:

-G6PD Genotyping Algorithm for Therapeutic Drug Recommendations

-Newborn Screen Follow-up for Glucose-6-Phosphate Dehydrogenase (G-6-PD) Deficiency

For more information, see Newborn Screening Act Sheet Glucose-6-Phosphate Dehydrogenase Deficiency in Special Instructions.

• Informed Consent for Genetic Testing
• Pharmacogenomic Associations Tables
• G6PD Genotyping Algorithm for Therapeutic Drug Recommendations
• Newborn Screening Act Sheet Glucose-6-Phosphate Dehydrogenase Deficiency
• Newborn Screen Follow-up for Glucose-6-Phosphate Dehydrogenase (G-6-PD) Deficiency
• Informed Consent for Genetic Testing (Spanish)

Polymerase Chain Reaction (PCR) followed by DNA Sequence Analysis