The Implications of a High Allelic Frequency of CYP2B6 G516T in Ethnic Chinese Persons

Open Access
Publisher Website
Google Scholar
Abstract
To the editor—The article by Ribaudo et al. [1] and the accompanying editorial commentary [2] have come at the right time to stimulate debates on how, with a global perspective, a treatment algorithm for HAART should be strategically developed to achieve maximum effectiveness. In the not-too-distant past, HAART was an expensive commodity of the Western world. With the expansion of treatment access, patients with HIV infection from varied ethnic origins are exposed to the same efficacious therapy, which is not without harmful consequences—toxicity and resistance emergence—if managed inappropriately. The poor metabolism of efavirenz, a once-daily nonnucleoside reverse-transcriptase inhibitor, in persons with the CYP2B6 G516T allele (also termed 2B6*6) is a case in point. The allelic frequency varies from 0.16 in the Japanese [3] and 0.14 in Koreans [4] to a much higher level of 0.42 in West Africans and 0.62 in Papua New Guineans [5], compared with an allelic frequency of 0.28 in white Americans. We set out to establish the allelic frequency in Chinese persons against the background of a rising number of patients with HIV who received a diagnosis in mainland China. Buffy coat specimens from 100 Chinese persons who donated blood were collected in October 2005 at the Hong Kong Red Cross Blood Transfusion Service. Direct sequencing was performed to screen for single-nucleotide polymorphisms, and restriction fragment–length polymorphism with the BsrI enzyme (New England Biolab) was used to confirm the G516 sequence. A total of 76 samples were successfully sequenced, yielding the following results: GG alleles in 28 samples, GT in 30 and TT in 18. The allelic frequency of G516T was high, at 0.43.
All Related Versions