Association of the OPRM1 and COMT genes' polymorphisms with the efficacy of morphine in Tunisian cancer patients: Impact of the high genetic heterogeneity in Tunisia?
BACKGROUND
Genetic causes for inter-individual variability response to opioids are clinical difficulties for treatment efficiency. The aim of the present study was to investigate the possible association of opioid treatment outcome with single nucleotide polymorphisms (SNPs) in the mμ opioid receptor (OPRM1) and catechol-o-methyltransferase (COMT) genes, in Tunisian cancer pain patients.


METHODS
We genotyped one hundred and twenty-nine cancer patients treated with different doses of morphine for 3 SNPs in OPRM1 gene (rs17174629, rs1799972 and rs1799971) and one in the COMT gene (rs4680). Associations between dose (continuous), dose escalation (yes/no) and SNP or haplotypes were investigated.


RESULTS
Unlike other studies on Caucasian and Chinese populations, no significant association were found between the 4 polymorphisms screened and the dose of morphine needed for pain relief.


CONCLUSIONS
This result can be explained by the genetic heterogeneity and cosmopolitan areas of our Tunisian patients compared to the others homogenous population.
Laboratoire de cytogénétique, de génétique moléculaire et de biologie de la reproduction humaine, CHU Farhat Hached, rue Ibn El Jezzar, 4002 Sousse, Tunisia. Electronic address: chatti.imen@yahoo.fr.
Imen
I
Chatti
Laboratoire de biochimie médicale, faculté de médecine, 63000 Clermont-Ferrand, France.
Isabelle
I
Creveaux
Inserm UMR 850, CHU Limoges, université Limoges, 87000 Limoges, France.
Jean-Baptiste
JB
Woillard
Laboratoire de biochimie médicale, faculté de médecine, 63000 Clermont-Ferrand, France.
Sarah
S
Langlais
Laboratoire de cytogénétique, de génétique moléculaire et de biologie de la reproduction humaine, CHU Farhat Hached, rue Ibn El Jezzar, 4002 Sousse, Tunisia.
Abdelbasset
A
Amara
Service de carcinologie, CHU Farhat Hached, 4002 Sousse, Tunisia.
Leila
L
Ben Fatma
Laboratoire de cytogénétique, de génétique moléculaire et de biologie de la reproduction humaine, CHU Farhat Hached, rue Ibn El Jezzar, 4002 Sousse, Tunisia.
Ali
A
Saad
Laboratoire de cytogénétique, de génétique moléculaire et de biologie de la reproduction humaine, CHU Farhat Hached, rue Ibn El Jezzar, 4002 Sousse, Tunisia.
Moez
M
Gribaa
Service de pharmacologie, hôpital Gabriel-Montpied, CHU de Clermont-Ferrand, 63000 Clermont-Ferrand, France; Inserm, U1107 NEURO-DOL, Clermont université, 63001 Clermont-Ferrand, France.
Frédéric
F
Libert
D000293:Adolescent; D000328:Adult; D000368:Aged; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D000072716:Cancer Pain / Q000188:drug therapy*; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D005260:Female; D018740:Genetic Heterogeneity; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000627:therapeutic use*; D020641:Polymorphism, Single Nucleotide; D017450:Receptors, Opioid, mu / Q000235:genetics*; D014416:Tunisia; D055815:Young Adult
D000701:Analgesics, Opioid; C485764:OPRM1 protein, human; D017450:Receptors, Opioid, mu; D009020:Morphine; C588010:COMT protein, human; D002394:Catechol O-Methyltransferase
Association; COMT; Cancer pain; Douleur du cancer; Genetic heterogeneity; Hétérogénéité génétique; OPRM1; Polymorphism; Polymorphisme