Question: Which population has a high frequency of the HLA-B*1502 allele?

Context:
A strong association between human leukocyte antigen (HLA)-B*1502 and CBZ-induced SJS/TEN has been reported in Han Chinese, Thai, Malaysian and Indian populations, but not in Caucasian or Japanese populations.
found a strong association between HLA-B*1502 and CBZ-induced SJS/TEN in the Han Chinese population from central and northern China. Combined with previous studies of the southern Han Chinese subpopulation, our results suggest that HLA-B*1502 is strongly associated with CBZ-induced SJS/TEN in the whole Han Chinese population.
A strong association between HLA-B*1502 and carbamazepine-induced SJS/TEN has been identified in Chinese and Thai.
In the present study, we conducted a pilot study to detect a possible association of oxcarbazepine (OXC)-induced MPE with HLA-B*1502 allele in Chinese Han population.
observed an increased frequency of HLA-B*1502 allele in patients (44.44%) compared with tolerant controls (11.11%), although it failed to reach statistical significance (P=0.294). CONCLUSIONS: Our findings indicate that HLA-B*1502 allele may contribute to the genetic susceptibility to OXC-induced MPE in Chinese Han population.
A strong association between HLA-B*1502 and CBZ-induced SJS/TEN has been reported in Han Chinese but not in Caucasian and Japanese populations. A case-control study was conducted to determine whether HLA-B*1502 is a valid pharmacogenetic test for SJS/TEN caused by CBZ in a Thai population.
Results from this study suggest that HLA-B*1502 may be a useful pharmacogenetic test for screening Thai individuals who may be at risk for CBZ-induced SJS and TEN.
A strong association has been reported between human leucocyte antigen (HLA)-B*1502 and carbamazepine-induced SJS in Han Chinese patients. European studies suggested that HLA-B*1502 is not a universal marker but is ethnicity-specific for Asians.
the human leukocyte antigen HLA-B*1502 is associated with Stevens-Johnson syndrome (SJS) induced by CBZ in Han Chinese.
the HLA allele B*1502 as a marker for carbamazepine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis in Han Chinese,
This allele is seen in high frequency in many Asian populations other than Han Chinese, but there are few data on whether the allele is a marker for this severe outcome in anyone other than Han Chinese.
a strong association between HLA-B*1502 and carbamazepine (CBZ)-induced Stevens-Johnson syndrome (SJS) in Han Chinese, but not in Caucasian populations.
A very strong association of carbamazepine-induced SJS with HLA-B*1502 has recently been described in the Han Chinese population.
there is a strong association in Han Chinese between a genetic marker, the human leukocyte antigen HLA-B*1502, and Stevens-Johnson syndrome induced by carbamazepine, a drug commonly prescribed for the treatment of seizures

Answer: HLA-B*1502 has a high frequency in Han Chinese and other Asian populations, except Japanese. (There is a strong association between human leucocyte antigen (HLA)-B*1502 and carbamazepine-induced Stevens-Johnson syndrome (SJS)).
Exact answer: Han Chinese and other Asian populations, except Japanese