Association of genetic variants with anti-tuberculosis drug induced hepatotoxicity: a high resolution melting analysis.
BACKGROUND
Tuberculosis (TB) treatment remains a challenge owing to the high incidence of drug induced hepatotoxicity (DIH). Apart from environmental factors, single nucleotide polymorphisms (SNPs) in drug metabolizing enzymes (DMEs), nuclear receptors (NRs) and transporter proteins (TPs) contribute to DIH. In the present study, we report known and novel SNPs in a total of seven genes of DMEs, NRs and TPs with high resolution melting (HRM) technique.


METHODS
DNA samples of 185 TB patients of Western Indian population, of which 50 showed DIH, were analyzed. Grouping of the temperature-shifted difference plots obtained from the DNA melt curves enables identification of known and novel SNPs. Representative samples of each group were sequenced.


RESULTS
We report 18 novel SNPs, of which 3 are in 5'-UTR, 14 in exonic and 1 in intronic region. Of the SNPs in exons, 7 non-synonymous, 3 synonymous and 4 deletion mutations were observed. Among the known SNPs, CYP2E1 wild-type, NAT2(∗)5 mutant and NAT2(∗)6 heterozygous genotypes were associated with DIH (p<0.05). Among the novel SNPs, group 2 of SLCO1B1 showed a significant association (p<0.05).


CONCLUSIONS
While several SNPs showed borderline p values between 0.05 and 0.15, the confidence in association can be improved further by using larger data sets.
Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India.
Meenakshi
M
Singh
Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India.
Vinod H
VH
Gupta
Department of Gastroenterology and Hepatology, Bombay Hospital and Medical Research Centre, Mumbai 400 020, India.
Deepak N
DN
Amarapurkar
Department of Pulmonary Medicine, BYL Nair Hospital, Mumbai 400 008, India.
Jyotsna M
JM
Joshi
Department of Gastroenterology and Hepatology, Jagjivanram Western Railway Hospital, Mumbai 400 008, India.
Rajiv
R
Baijal
Department of Gastroenterology and Hepatology, Jagjivanram Western Railway Hospital, Mumbai 400 008, India.
Praveenkumar H
PH
Ramegowda
Department of Pathology, TN Medical College, Mumbai 400 008, India.
Anjali D
AD
Amarapurkar
Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India. Electronic address: wangikar@iitb.ac.in.
Pramod P
PP
Wangikar
D000995:Antitubercular Agents / Q000009:adverse effects* / Q000378:metabolism; D056486:Chemical and Drug Induced Liver Injury / Q000235:genetics*; D015331:Cohort Studies; D056726:Genetic Association Studies / Q000379:methods*; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D017422:Sequence Analysis, DNA; D014376:Tuberculosis / Q000150:complications* / Q000188:drug therapy / Q000473:pathology
D000995:Antitubercular Agents
Drug induced hepatotoxicity; High resolution melting; Mutation screening; Tuberculosis