Glucose-6-Phosphate Dehydrogenase Deficiency (G6PD) Sequencing

Background Information for Glucose-6-Phosphate Dehydrogenase Deficiency (G6PD) Sequencing:
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.