Ordering Recommendation

Use to identify patients who may be at risk for developing Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) prior to treatment with carbamazepine (CBZ). Recommended for patients not currently taking CBZ.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Lavender (EDTA), pink (K 2 EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Transport 5 mL whole blood. (Min: 3 mL)

Storage/Transport Temperature


Unacceptable Conditions

Specimens collected in green (sodium or lithium heparin).


Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable


Polymerase Chain Reaction (PCR)
Sequence-Specific Oligonucleotide Probe Hybridization
Massively Parallel Sequencing




3-7 days

Reference Interval

By report

Interpretive Data

Background Information for HLA-B*1502 Genotype, Carbamazepine Hypersensitivity:
Carbamazepine (CBZ) is an aromatic antiepileptic drug, approved for the treatment of epilepsy and trigeminal neuralgia. Rarely, CBZ can induce severe life threatening reactions such as Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN). Symptoms usually appear within the first months of treatment, and include skin rash, hives, sores in the mouth, blistering or peeling of the skin, and erosion of the mucous membranes in the respiratory and gastrointestinal tract. The presence of HLA-B*15:02 increases risk for CBZ-induced SJS/TEN in individuals of Asian ancestry. The incidence of CBZ-induced life-threatening reactions such SJS, TEN, or hypersensitivity syndrome (HSS) is 1-10 per 10,000, which can be higher in some Asian countries.
Incidence: HLA-B*15:02 allele frequency varies by ethnicity, with highest incidence in Asians: 10.2 percent in Han Chinese, 10 percent in Taiwanese (18 percent in indigenous Puyuma), greater than 5 percent in the populations of Hong Kong, Thailand, Malaysia, Vietnam, Philippines, India (Khandesh and West Bhil) and Indonesia. Frequency is low in African Americans (0.1-1 percent) and less than 0.1 percent in Caucasians.
Cause: In patient of Asian descent, CBZ-induced SJS/TEN is strongly associated with the presence of HLA-B*15:02 allele. The mechanism is immune mediated and involves drug-induced changes in peptide presentation by HLA-B*15:02, which allows for the activation of self-reactive T lymphocytes. Activated immune cells contribute to the cellular death of keratinocytes in the skin, which causes the epidermal destruction and detachment of the skin seen in SJS/TEN.
Alleles tested: HLA-B*15:02 allele. Other members of the HLA B75 serogroup detected by this assay can also be associated with carbamazepine-induced SJS/TEN.
Clinical Sensitivity and Specificity: 80-97 percent and 99 percent, respectively in populations where the HLA-B*15:02 allele is common.
Methodology: PCR followed by Sequence Specific Oligonucleotide Probe Hybridization of HLA-B locus.
Analytical Sensitivity and Specificity: Greater than 99 percent.
Limitations: Copy number of HLA-B*15:02 allele will not be reported.

Test systems were developed and their performance characteristics determined by the H&I laboratory at the University of Utah Health, under the accreditation guidelines from the American Society for Histocompatibility and Immunogenetics (ASHI).

Compliance Category

Performed by non-ARUP Laboratory


Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
2012050 HLA-B*15:02
* 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.


  • HLA B*1502, Carbamazepine Sensitivity
  • HLA-B 1502 Genotype, Carbamazepine Hypersensitivity
  • HLA-B*1502 Typing
HLA-B*15:02 Genotyping, Carbamazepine Hypersensitivity