Techno e lo en g y Al-Haggar, Gene Technology 2014, 3:1 G Gene Technology DOI: 10.4172/2329-6682.1000107 ISSN: 2329-6682 Review Article Open Access SNPs as Co-morbid Factors for Drug Abuse and Ischemic Heart Disease Mohammad Al-Haggar* Pediatrics and Genetics, Mansoura University Children's Hospital (MUCH), 35516 Mansoura, Egypt Abstract Drug abuse is a major health and social problem that may be associated with morbidity and mortality. It is considered by many societies as an antisocial or even criminal behavior. Susceptibility to addiction is multifactorial with complex genetic basis characterized by phenotypic and genetic heterogeneity. Candidate genes are those concerned with action and metabolism of abused drug or those that encode neurotransmitter systems. Comorbidity means the concomitance or sequential development of two disorders in one cohort. High prevalence of comorbidities does not mean that one condition caused the other, even if one appeared first. Neurocardiac involvement may be in the form of the heart’s effects on the brain as in embolic stroke as a sequel of cardiac disease, the brain’s effects on the heart as in neurogenic heart disease, and neurocardiac syndromes like Friedreich's ataxia. Recently, increasing evidences suggest genetic and epigenetic factors as a cause of comorbidity. Single nucleotide polymorphisms (SNPs) is the most interesting risk factor that could explain the personal variation in disease susceptibility especially the multifactorial comorbid disorders. In this article, we will review the role SNPs as a risk factor for the comorbidity of drug abuse and ischemic heart disease. Keywords: Substance abuse; Ischemicheart; SNPs these factors may influence the comorbidity, many studies are currently focusing on the role SNPs as risk factor. Introduction In this article, we are review the role SNPs as a risk factor for the Drug abuse is a major concern that impacts all levels of society [1]. comorbidity of drug abuse and ischemic heart disease whatever who Generally, drug abuse is considered by many societies, an antisocial or comes first. even criminal behavior. Drug abuse is a major health and social issue for its morbidity and mortality, individual and society cost, violence Biological components of substance abuse and legal problems involvement. It is widely known that dependence on Drug/substance abuse and dependence are complex phenomena drugs of abuse is moderately to strongly heritable but, the susceptibility that defy simple explanation or description. The abusive use of to addiction has a complex genetic basis characterized by phenotypic addictive drugs is a medical and social problem as old as recorded and genetic heterogeneity. Candidate genes are both specific genes, human history. Ancient references to drug abuse may be found in the related to action and metabolism of drug of abuse, and non-specific oral and written traditions of virtually all ethnic and cultural groups genes that encode neurotransmitter systems that could influence the on the planet [6]. One of the most striking features of drug addiction biological activity of the drug [2]. is how few chemicals are subject to abuse. Among all congeners of all When two disorders or illnesses occur simultaneously in the same known chemicals, approximately 30,000,000 chemical substances, yet, person, they are called comorbid. Surveys show that drug abuse and only approximately 100 (including nicotine, ethanol, psychostimulants, other mental illnesses are often comorbid. Six out of ten people with a opiates, barbiturates, benzodiazepines and cannabinoids) are addictive substance use disorder also suffer from another form of mental illness. which is a stunningly small subset of the overall chemicals [7]. Many But the high prevalence of these comorbidities does not mean that one contributing factors including the actions and effects the drug could condition caused the other, even if one appeared first. In fact, there are underlie the substance abuse and dependence. In order to understand at least three scenarios that should be considered; (1) drug abuse can substance abuse disorder one must first understand how drugs work in cause a mental illness,(2) mental illness can lead to drug abuse, and (3) the brain, why certain drugs have the potential for abuse, and what, if drug abuse and mental disorders are both caused by other common any, biological differences exist among individuals in their susceptibility risk factors. In reality, all three scenarios can contribute, in varying to abuse drugs [8]. degrees, to the establishment of specific comorbid mental disorders and The earlier onset of drug intake is associated with greater likelihood addiction [3]. Although a variety of diseases commonly co-occur with of development of substance use problems. However, there is debate drug abuse and addiction (e.g. HIV, hepatitis C, cancer, cardiovascular about whether early onset uniquely affects brain development in such disease), most researches in this era focus only on the comorbidity of a way as to promote pathological behavior or whether the same genetic drug use disorders and other mental illnesses [3]. Neurocardiology has and environmental factors that make an individual likely to develop many dimensions and can be divided into three major categories: the drug problems also make them likely to initiate early [9]. In the U.K. and heart’s eff ects on the brain e.g. cardiac source embolic stroke, the brain’s North America, the understanding of addiction has been dominated by effects on the heart e.g. neurogenic heart disease, and neurocardiac syndromes e.g. Friedreich's disease [4]. In recent years, increasing evidences suggest that genetic and *Corresponding author: Prof. Mohammad Al-Haggar, Pediatrics and Genetics, epigenetic factors could be involved in disease comorbidity. Given Mansoura University Children's Hospital (MUCH), 35516 Mansoura, Egypt, the central role of the genome and proteome in biology and patho- Tel: +20-50-2310661/+2-011117-15350; Fax: +20-50-2234092; E-mail: [email protected] biology, it is safe to predict that misregulation of specific gene(s) and gene expression defects could influence the disease state and hence play Received January 20, 2014; Accepted February 06, 2014; Published February 10, 2014 a role in co-morbid disorders. Genes and Gene expression products are essential for the development and function of the brain and heart. Citation: Al-Haggar M (2014) SNPs as Co-morbid Factors for Drug Abuse and Ischemic Heart Disease. Gene Technology 3: 107. doi: 10.4172/2329- DNA, SNPs, polymorphisms and changes in miRNA expression profiles 6682.1000107 leading to an increased risk for developing neurodegenerative disorders as well as heart failure [5]. Previous researches have demonstrated Copyright: © 2014 Al-Haggar M. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted genetic and environmental influences on drug use disorders and use, distribution, and reproduction in any medium, provided the original author and cardiovascular risks separately, but there are less known about how source are credited. Gene Technology Volume 3 • Issue 1 • 1000107 ISSN: 2329-6682 GNT, an open access journal Citation: Al-Haggar M (2014) SNPs as Co-morbid Factors for Drug Abuse and Ischemic Heart Disease. Gene Technology 3: 107. doi: 10.4172/2329- 6682.1000107 Page 2 of 10 the disease theory and the social learning theory; implications of the Genetic components of substance abuse disease theory depend on the notion that addiction is caused by some irreversible deficiency or pathology and that treatment is, therefore, The abuse liability of a drug is a measure of the likelihood that primarily a medical concern. Certain conclusions inevitably follow its use will result in drug dependence. Many factors ultimately play a from such a premise: (1) abstinence is the only treatment goal, (2) loss role in an individual’s drug-taking behavior; nevertheless, the abuse of control is the hallmark feature, (3) patients are not responsible for potential of a drug is related to its intrinsic rewarding properties and/ their illness, (4) therapists tend to be medical practitioners, and, finally, or the neuroadaptive responses that result from its prolonged use. (5) community-based prevention will be ineffective [10]. Pharmacological drug criteria e.g. reinforcing effect, tolerance, and physical dependence are drug-related factors; reinforcing effect is There are 10 markers of substance dependence that translate the essential for significant abuse potential, whereas tolerance and physical biopsychosocial status of substance abuser; 1) Preoccupation with dependence are not absolutely required [14]. Liability is a measure drinking or taking drugs, 2) Salience of substance use behavior, 3) for the role genetic factor in multifactorial traits which is sometimes Compulsion to start using alcohol or drugs, 4) Planning alcohol- or drug- termed as heritability. There is no natural clear-cut gap between the related behaviors, 5) Maximizing the substance effect, 6) Narrowing of norm and pathology [15]. For instance, while the essence of addiction substance use repertoire, 7) Compulsion to continue using alcohol and is considered to be compulsive drug seeking and use [16], the diagnosis drugs, 8) Primacy of psychoactive effect, 9) Maintaining a constant of substance dependence is defined as the presence of any three or more state (of intoxication), 10) Expectations of need for substance use. Two of the seven symptoms, such as tolerance or taking substance often in biological factors contribute to substance abuse and addiction: the larger amounts than intended. None of the symptoms are necessary or effects drugs of abuse exert on the individual, and the biological status of sufficient for the diagnosis, which makes the definition of the threshold the individual taking drugs. The former relates to the acute mechanisms even more uncertain. This uncertainty is one of the reasons making of abused drug action in the brain and the long-term effects on chronic these disorders heterogeneous. Abuse liability is justified by the well exposure.