Background: A variety of genetic pathways have been described as being essential
in drug abuse and myocardial ischemia (MI), including dopamine-2 receptor gene
(DRD2) and serotonin transporter gene (SERT). However, there is insufficient information
on how those genetic pathways could contribute to their comorbidity.
Objectives: The study aimed to examine the potential association between drug
abuse/myocardial ischemia comorbidity and five single nucleotide polymorphisms (SNPs)
of DRD2 gene; Taq IA, Taq IB, Taq ID, -241A>G, and -141C del/ins, and two SNPs of
SERT gene; 5-HTTLPR (rs25531) and an intronic variant (Stin2).
Method: Fifteen Egyptian families including 211 individuals and 75 control subjects were
genotyped using PCR-RFLP assay method. All individuals were assessed using drug use
survey and complete cardiovascular profile.
Results: The odds ratio (OR) for comorbidity with early onset MI associated with the
A1A1 genotype of TaqIA was 3.9 (95% CI=1.8-8.5). However, B1B1 and B1B2 genotypes
of TaqIB were significant in comorbidity of early onset drug abuse phenotype (OR
=2.6, 95% CI=1.4-5.2 and OR=1.7 and 95% CI=1.2-2.5 respectively). Genotype AG of -
241A˃G showed higher risk among comorbid subjects of early onset drug abuse (OR=1.9,
95% CI=1.4-2.7) and ins-containing genotypes of -141C del/ins were significant in comorbidity.
Regarding SERT gene, SLA genotype of 5-HTTLPR and 10/10 of STin2 were
significantly associated with comorbidity of early onset MI with OR=1.5, 95% CI=1.1-2.2
and OR=3.3, 95% CI=1.5-6.9.
Conclusion: SNPs of the studied genes have made a significant contribution to comorbidity
however, further studies are needed to validate the results in a wider population.