Platelet Antigen Genotyping Panel
Ordering Recommendation

Use in risk assessment for fetal or neonatal alloimmune thrombocytopenia. May be ordered for parental, fetal, or neonatal genotyping.

Polymerase Chain Reaction/Fluorescence Monitoring
Mon, Thu
2-7 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Fetal Genotyping: Amniotic fluid OR two T-25 flasks at 80 percent confluency of cultured amniocytes. If the client is unable to culture amniocytes, this can be arranged by contacting ARUP Client Services at (800) 522-2787. 
WITH Maternal Cell Contamination Specimen 
(see Remarks)Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
Parental Genotyping:
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B). 
Specimen Preparation
Amniotic Fluid: Transport 10 mL unspun fluid. (Min: 5 mL)
Cultured Amniocytes: Fill flasks with culture media. Transport two T-25 flasks at 80 percent confluency of cultured amniocytes filled with culture media. Backup cultures must be retained the client's institution until testing is complete.
Maternal Cell Contamination Specimen:
Transport 3 mL whole blood (Min: 1 mL)
Whole Blood (Parental Genotyping):
Transport 3 mL whole blood. (Min: 1 mL) 
Storage/Transport Temperature
Amniotic fluid: Room temperature.
Cultured Amniocytes: CRITICAL ROOM TEMPERATURE. Must be received within 48 hours of shipment due to liability of cells.
Whole Blood or Maternal Cell Contamination Specimen:
Unacceptable Conditions
Maternal specimen is recommended for proper test interpretation if contamination of the fetal specimen from the mother is suspected. Order Maternal Cell Contamination. Patient History Form is available on the ARUP Web site or by contacting ARUP Client Services. 
Fetal Specimen: Ambient: 48 hours; Refrigerated: Unacceptable; Frozen: Unacceptable
Whole Blood or Maternal Cell Contamination Specimen: Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable 
Reference Interval
Test Number
Reference Interval
0051309Platelet Antigen 1 Genotyping (HPA-1)By report
0051310Platelet Antigen 2 Genotyping (HPA-2)By report
0051311Platelet Antigen 3 Genotyping (HPA-3)By report
0051490Platelet Antigen 4 Genotyping (HPA-4)By report
0051312Platelet Antigen 5 Genotyping (HPA-5)By report
0051313Platelet Antigen 6 Genotyping (HPA-6)By report
0051314Platelet Antigen 15 Genotyping (HPA-15)By report

Interpretive Data
Background Information for Platelet Antigen Genotyping Panel:
Spontaneous fetal intracranial bleeding may occur in 20 percent of severe perinatal alloimmune thrombocytopenia (PAT) affected pregnancies; there is a risk of fetal death. Post-transfusion purpura may occur in transfusion recipients with antibodies to a specific platelet antigen.
PAT occurs in 1 in 5000 births.
For women homozygous for a rare "b" HPA allele with antibodies to the common "a" allele, there is a 50 percent risk a pregnancy will be affected if her partner is heterozygous for the "a" allele and 100 percent risk if her partner is homozygous for the "a" allele.
Maternal-fetal HPA incompatibility.
Polymorphisms Tested: HPA-1 (GPIba) c.176T>C, p.L59P; HPA-2 (GPIba) c.482C>T p.T161M; HPA-3 (GPIIb) c.2621T>G p.I874S; HPA-4 (GPIIIa) c.506G>A p. R169Q; HPA-5 (GPIa) c.1600G>A p.E534K; HPA-6 (GPIIIa) c.1544G>A p.R515Q; HPA-15 CD109 c.2108A>C p.Y703S; "a" (common) and "b" (variant) alleles (see below).
Clinical Sensitivity: Unknown.
PCR followed by fluorescent monitoring.
Analytic Sensitivity and Specificity: 99 percent.
Bloody amniotic fluid specimens may give false-negative results because of maternal cell contamination. Specificity may be compromised by mutations in primer sites. Diagnostic errors can occur due to rare sequence variations.
Informed consent: Recommended; forms are available at

This test is performed pursuant to an agreement with Roche Molecular Systems, Inc.

HPA 1-6, 15 Polymorphism
HPA System
"a" Allele Common
"b" Allele Variant

Compliance Statement C: The performance characteristics of this test were validated by ARUP Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test. However, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. ARUP is authorized under Clinical Laboratory Improvement Amendments (CLIA) and by all states to perform high-complexity testing. Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

CPT Code(s)
81400 x7
Component Test Code*Component Chart NameLOINC
0051315Platelet Antigen Panel Interpretation
0051320Platelet Antigen 1 Genotyping
0051322Platelet Antigen 2 Genotyping
0051324Platelet Antigen 3 Genotyping
0051326Platelet Antigen 5 Genotyping
0051328Platelet Antigen 6 Genotyping
0051330Platelet Antigen 15 Genotyping
0051489Platelet Antigen 4 Genotyping
2001318Platelet Antigen Panel Specimen
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
  • HPA platelet antigen genotyping panel