Test Code: CD33SN

Genes: (0 genes)

Sample Type: 30 ml peripheral blood in EDTA (purple/pink top) tube, refrigerated; 2-5 ml of bone marrow aspirate in EDTA (purple/pink top) tube, refrigerated

Method:

Turnaround Time: 10 Days

Courier: Ship overnight at room temperature to receive next day. Do not refrigerate or freeze. Maintain specimen at room temperature.

Price: 900

Description:
An NGS based assay of the CD33 rs12459419 (dbSNP) polymorphism, leveraging on amplicon sequencing to differentiate between C and T alleles. The CC genotype appears to have a substantial response to Gemtuzumab Ozogamicin (GO), whereas, CT or TT genotypes are associated with a suboptimal response to GO. The c.41C>T (p.Ala14Val) variant alters the exonic splicing enhancer (ESE) binding site for SRSF2 which has been associated to skipping of exon2, resulting in the shorter CD33 isoform (D2-CD33), which lacks the IgV domain. Detection of CD33 isoforms without exon2-encoding IgV domain is clinically important because this domain contains the immune-dominant epitope (hP67.6) which is used for diagnostic immunophenotyping, and the target for the antibody that is conjugated to calicheamicin in GO and other CD33 targeted therapies.