Significance of serum VIP and PACAP in multiple sclerosis: an exploratory case-control study.

BACKGROUND: Multiple sclerosis (MS) is a chronic inflammatory neurodegenerative disease of the central nervous system. Vasoactive and intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP) are neuropeptides that play roles in anti-inflammation and neuroprotection in MS. In this study, we aimed to determine the serum levels of VIP and PACAP in MS patients versus healthy controls and to correlate them with demographics and clinical characteristics. METHODS: Serum samples were collected from MS patients (n = 145) and healthy controls (n = 73) to measure serum levels VIP and PACAP. RESULTS: VIP serum levels were lower in MS patients than healthy controls (p < 0.001). Serum PACAP levels were the same among the two groups. Gender-based analysis showed that VIP levels were lower in healthy females (1238.840 pg/ml) than healthy males (3300.105 pg/ml; p < 0.001), and PACAP serum levels were significantly lower in male MS patients (48,516.214 fg/ml) than female MS patients (62,466.400 fg/ml; p = 0.029). ROC curve suggested that serum VIP level can discriminate patients with MS from healthy controls. Relapsing-remitting MS, progressive-MS, and clinically isolated syndrome groups were different in age, MS disease duration, EDSS score, and VIP levels (p < 0.05). MS disease type and history of previous relapses in the preceding 24 months predicted serum VIP levels, while gender predicted PACAP levels. CONCLUSION: VIP serum levels are decreased in MS patients and can be used to differentiate between MS patients and healthy controls. Further studies with larger sample sizes are required to investigate VIP as a marker to reflect MS disease progression.

Alpha Calcitonin Gene-related Peptide, Neuropeptide Y, and Substance P as Biomarkers for Diagnosis and Disease Activity and Severity in Multiple Sclerosis.

BACKGROUND: Alpha calcitonin gene-related peptide (aCGRP), neuropeptide Y (NPY), and substance P (SP) are neuropeptides that have emerged recently as potent immunomodulatory factors with potential as novel biomarkers and therapeutic targets in multiple sclerosis (MS). OBJECTIVE: The study aimed to detect serum levels of aCGRP, NPY, and SP in MS patients versus healthy controls and their association with disease activity and severity. METHODS: Serum levels were measured in MS patients and age and sex-matched healthy controls using ELISA. RESULTS: We included 67 MS patients: 61 relapsing-remitting MS (RR-MS) and 6 progressive MS (PR-MS), and 67 healthy controls. Serum NPY level was found to be lower in MS patients than in healthy controls (p < 0.001). Serum aCGRP level was higher in PR-MS compared to RR-MS (p = 0.007) and healthy controls (p = 0.001), and it positively correlated with EDSS (r = 0.270, p = 0.028). Serum NPY level was significantly higher in RR-MS and PR-MS than in healthy controls (p < 0.001 and p = 0.001, respectively), and it was lower in patients with mild or moderate/severe disease than in healthy controls (p < 0.001). Significant inverse correlations were found between SP level and MS disease duration (r = -0.279, p = 0.022) and duration of current DMT (r = -0.315, p = 0.042). CONCLUSION: Lower serum levels of NPY were revealed in MS patients compared to healthy controls. Since serum levels of aCGRP are significantly associated with disease activity and severity, it is a potential disease progression marker.

Clinical, molecular, and drug resistance epidemiology of HIV in Jordan, 2019-2021: A national study.

BACKGROUND: Limited epidemiologic studies have been conducted in Jordan describing the HIV epidemic. This study aimed to address this gap to inform HIV prevention and control. METHODS: A nationally-representative cross-sectional study was conducted among adults living with HIV in Jordan. Laboratory testing included HIV viral load and next-generation-sequencing-based clinical genotype. Log-binomial regression estimated risk ratios (RRs) and 95% confidence intervals (CIs). RESULTS: Among 231 (70%) participants, most were male (184/80%), and from Jordan (217/94%). Among 188 treatment-experienced-participants (>6 months), 165 (88%) were virally suppressed. High-level resistance was most frequent against nucleoside reverse transcriptase inhibitor (13/81%), and integrase-strand transfer inhibitor (INSTI) (10/62%) drugs among viremic (≥1000 HIV copies/mL) treatment-experienced participants with drug-resistant mutations (DRMs, n = 16). Common HIV subtypes (n = 43) were B (6/14%), A1 (5/12%), and CRF01_AE (5/12%); additionally, novel recombinant forms were detected. In multivariate analysis, independently higher risk for late diagnosis (n = 49) was observed with diagnosis through blood donation (vs check-up: RR 2.20, 95%CI 1.16-4.17) and earlier time-period of diagnosis (1986-2014 vs 2015-2021: RR 2.87, 95%CI 1.46-5.62). CONCLUSIONS: Late diagnosis and INSTI resistance endanger national HIV prevention and treatment in Jordan-high-level resistance to INSTI suggests therapeutic drug monitoring is needed for treatment efficacy and conservation of treatment options.

MicroRNA profiling in dogs undergoing induced ischemic heart infarction: An experimental study.

Background and Aim: MicroRNAs (miRNAs) play an important role in various biological functions. According to many studies, miRNA expression is tissue-specific, strongly controlled throughout embryogenesis, and over- or under-expressed in numerous disorders, including cardiovascular pathologies. This study aimed to screen, characterize, and profile many induced biomarkers (miRNAs) in dog serum before and after experimentally inducing a regional myocardial infarction (MI) by occluding the coronary arteries under general anesthesia. Materials and Methods: A preclinical experimental animal study recruited 12 healthy canine dogs. The selected canine dogs were anesthetized with 1 mg/kg xylazine and 15 mg/kg ketamine before undergoing femoral arterial catheterization under fluoroscopic supervision. Commercial assay kits were used to purify total RNA and miRNA before the occlusion and 2 h after the occlusion according to the manufacturer's guidelines, and the samples were stored in RNase/DNase-free water at -80°C. Data were analyzed by GraphPad Prism 5.0 software (GraphPad Prism, San Diego, CA) SPSS, and GenEx software (www.multid.se) or (REST V3). Results: Among 325 transcribed genes, 20 were identified in 2 h. After MI, 14 biomarkers were negative, indicating downregulation, and 6 (3-F08, 3-B10, 4-A11, 1-A06, 2-E01, 3-F10) were positive, indicating upregulation. Polymerase chain reaction assay results showed a normalized fold-change in gene expression in the test sample. Fold values >1 represented a biologically significant change. Conclusion: Profiling of miRNAs before and after MI in a dog model revealed upregulation of six previously unidentified biomarkers (3-F08, 3-B10, 4-A11, 1-A06, 2-E01, and 3-F10), indicating various miRNA regulatory patterns.

Cytomegalovirus and Epstein-Barr Virus Co-infection in a Patient With Chronic Granulomatous Disease Co-existing With Familial Mediterranean Fever and Early-Onset Inflammatory Bowel Disease: A Case Report.

The association between primary immunodeficiencies and autoinflammatory disorders has been popularized over the past decade. In this report, we illustrated the co-infection of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) in a three-year-old Jordanian male patient with an extremely rare variant of the CYBB gene (c.125C>G, p.Thr42Arg) associated with chronic granulomatous disease (CGD) coexisting with familial Mediterranean fever (FMF). CGD and FMF co-existence induced early-onset inflammatory bowel disease mainly resembling Crohn's disease.

A Novel ANO1 Gene Variant is Associated with Intestinal Dysmotility Syndrome Masquerading as Hirschsprung Disease: A Case Report.

Anoctamin 1 (ANO1)-related intestinal dysmotility syndrome (OMIM: 620045) is an extremely rare disorder with only 2 cases reported in the medical literature. We present the clinical scenario of a 2-month-old male infant that presented to our center with diarrhea, vomiting, and abdominal distension. Routine investigations did not yield a clear diagnosis. Whole-exome sequencing showed a novel homozygous nonsense ANO1 pathogenic variant (c.1273G>T) with a protein alternation of p.Glu425Ter that fits the patient's phenotype. Sanger sequencing revealed the same ANO1 variant in both parents in a heterozygous form confirming an autosomal recessive mode of inheritance. The patient experienced multiple bouts of diarrhea-related metabolic acidosis, dehydration, and severe electrolyte imbalances that required intensive care unit monitoring. The patient was managed conservatively and being followed regularly in an outpatient setting.

Regional connectivity drove bidirectional transmission of SARS-CoV-2 in the Middle East during travel restrictions.

Regional connectivity and land travel have been identified as important drivers of SARS-CoV-2 transmission. However, the generalizability of this finding is understudied outside of well-sampled, highly connected regions. In this study, we investigated the relative contributions of regional and intercontinental connectivity to the source-sink dynamics of SARS-CoV-2 for Jordan and the Middle East. By integrating genomic, epidemiological and travel data we show that the source of introductions into Jordan was dynamic across 2020, shifting from intercontinental seeding in the early pandemic to more regional seeding for the travel restrictions period. We show that land travel, particularly freight transport, drove introduction risk during the travel restrictions period. High regional connectivity and land travel also drove Jordan's export risk. Our findings emphasize regional connectedness and land travel as drivers of transmission in the Middle East.

Characterization of surface proteins of Cronobacter muytjensii using monoclonal antibodies and MALDI-TOF Mass spectrometry.

BACKGROUND: Cronobacter spp. is a newly emerging pathogen that causes meningitis in infants and other diseases in elderly and immunocompromised individuals. This study was undertaken to investigate surface antigenic determinants in Cronobacter spp. using monoclonal antibodies (MAbs) and MALDI-TOF Mass spectrometry. RESULTS: Spleenocytes from mice that were immunized with heat-killed (20 min, 80°C) Cronobacter cells were fused with SP2 myeloma cells. Five desirable MAbs (A1, B5, 2C2, C5 and A4) were selected. MAbs A1, B5, 2C2 and C5 were of IgG2a isotype while A4 was an IgM. Specificity of the MAbs was determined by using immunoblotting with outer membrane protein preparations (OMPs) extracted from 12 Cronobacter and 6 non-Cronobacter bacteria. All MAbs recognized proteins with molecular weight ranging between 36 and 49 kDa except for one isolate (44) in which no OMPs were detected. In addition, MAbs recognized two bands (38-41 kDa) in four of the non-Cronobacter bacteria. Most of the proteins recognized by the MAbs were identified by MALDI-TOF peptide sequencing and appeared to be heterogeneous with the identities of some of them are still unknown. All MAbs recognized the same epitope as determined by an additive Index ELISA with their epitopes appeared to be conformational rather than sequential. Further, none of the MAbs recognized purified LPS from Cronobacter spp. Specificity of the MAbs toward OMPs was further confirmed by transmission electron microscopy. CONCLUSIONS: Results obtained in this study highlight the immunological cross-reactivity among Cronobacter OMPs and their Enterobacteriaceae counterparts. Nevertheless, the identity of the identified proteins appeared to be different as inferred from the MALDI-TOF sequencing and identification.

Characterizing and Profiling microRNAs in Dogs Undergoing Induced Ischemic Brain Stroke After Middle Cerebral Artery Occlusion Under Fluoroscopic Guidance.

PURPOSE: Ischemic stroke of the brain is still considered one of the most common causes of disability and death in developed and developing countries in human beings despite advances in medicine and technology. This study was conducted to characterize and profile tens of induced biomarkers (microRNAs) after experimentally inducing regional ischemic stroke of the brain by occluding the middle cerebral artery under fluoroscopic guidance using an autologous blood clot. PATIENT AND METHODS: A total of six healthy dogs were recruited for this study. The microRNAs were profiled in the blood and urine before and after occluding the middle cerebral artery using genetic techniques. RESULTS: The very highly expressed genes were comprised within cluster A, followed by cluster D in both 24 and 48-hour brain samples. Clusters B and C revealed down-regulated genes, while miRNAs remained up-regulated in the 24-hour samples merely in cluster F. Upregulated genes at 48 hours of reperfusion were included in cluster E. On the other hand, changes were observed after a day on the cluster G genes. Exclusive upregulation was notified after 2 days due to the changes in mIR-138. The normalized gene expression in the test sample is witnessed through Fold-Change, which divides the control sample's normalized gene expression. Moreover, fold-change has emerged as a significant approach for representing fold-regulation. CONCLUSION: The microRNAs expression in blood and urine may have a potential role in the diagnosis, prognosis, and assessment of therapy associated with cerebral artery occlusion under fluoroscopic guidance.

Inhibition of MEK sensitizes paclitaxel-induced apoptosis of human colorectal cancer cells by downregulation of GRP78.

Here we report that paclitaxel induces variable degrees of apoptosis in human colorectal cancer cells. Paclitaxel induces multiple arms of the endoplasmic reticulum stress response, including upregulation of the 78-kDa glucose-regulatory protein (GRP78) and eukaryotic initiation factor alpha phosphorylation. Inhibition of the MEK/ERK pathway sensitized colorectal cancer cells to paclitaxel-induced apoptosis. A similar result was obtained by the inhibition of GRP78 using small interfering RNA molecules. Knockdown of MEK resulted in a significant downregulation of paclitaxel-induced upregulation of GRP78 indicating that activation of GRP78 is a downstream event of MEK/ERK pathway activation. These results indicate that GRP78 might be a novel mechanism underlying the resistance of colorectal cancer cells to microtubule-targeting drugs. A combination of compounds capable of suppressing GRP78 might be a golden approach for improving the effectiveness of taxanes.

Horizontal gaze palsy and progressive scoliosis with two novel ROBO3 gene mutations in two Jordanian families.

BACKGROUND: Horizontal gaze palsy and progressive scoliosis (HGPPS) is a rare autosomal recessive disorder due to mutations in ROBO3 gene. Patients have characteristic clinical and imaging findings. We report six patients from two families with this disorder with two novel mutations. MATERIALS AND METHODS: One patient from a non-consanguineous family and five patients from extended consanguineous families were clinically and radiologically examined. Blood samples from the patients and their parents were obtained and all the coding exons and flanking intronic sequences of the ROBO3 gene were amplified and subjected to bidirectional DNA sequencing. RESULTS: All six patients had the characteristic clinical and radiological findings of HGPPS. Genetic testing showed two novel mutations including frame-shift and nonsense. CONCLUSION: Two novel mutations in the ROBO3 gene were identified in two Jordanian families with six affected individuals. To our knowledge, this is the first molecular study of HGPPS in Jordan.

The effect of combined treatment with sodium phenylbutyrate and cisplatin, erlotinib, or gefitinib on resistant NSCLC cells.

BACKGROUND: Chemotherapy resistance is the main cause of the marginal clinical benefit of platinum-based chemotherapy and tyrosine kinase inhibitors in advanced non-small-cell lung cancer (NSCLC). Thus, the identification of new therapeutic agents that can enhance the sensitivity of these drugs is of clinical importance. Histone deacetylase inhibitors (HDACIs) are emerging as new promising agents with strong antiproliferative effects against different types of cancers. This study investigates the synergistic potential of sodium phenylbutyrate (NaPB) added on top of standard chemotherapy used against NSCLC. OBJECTIVE: The objective of this study was to evaluate the ability of NaPB to overcome the resistance of NSCLC cell lines to cisplatin, gefitinib, and erlotinib. METHODS: MTT cell proliferation assay was used to measure the anticancer effects of cisplatin, erlotinib, or gefitinib alone or combined with various concentrations of NaPB against A549, Calu1, and H1650 NSCLC cell lines. Synergism was estimated by measuring synergy value (R), which is equal to the ratio of IC50 of each primary drug alone divided by combination IC50s. Student's t-test analysis was used to evaluate the potential differences between IC50 values. ANOVA followed by Tukey's post hoc was used to evaluate the potential differences among monotherapy and combination treatment groups. Analyses were performed using R 3.3.2 software. P-value <0.05 was considered to be statistically significant. RESULTS: NaPB was shown to inhibit the growth of A549, Calu1, and H1650 cell lines in a dose-dependent manner (IC50 10, 8.53, and 4.53 mM, respectively). Furthermore, the addition of NaPB along with cisplatin, erlotinib, or gefitinib to A549, Calu1, and H1650 cell lines resulted in a synergistic antiproliferative effect against the three NSCLC cell lines (R>1.6, P-value <0.05), thus suggesting that NaPB can potentiate the effect of cisplatin, erlotinib, and gefitinib on A549, Calu1, and H1650 cell lines. CONCLUSION: Current results suggest a potential role of NaPB as a sensitizing agent in NSCLC.

Transcriptome analysis of mouse stem cells and early embryos.

Understanding and harnessing cellular potency are fundamental in biology and are also critical to the future therapeutic use of stem cells. Transcriptome analysis of these pluripotent cells is a first step towards such goals. Starting with sources that include oocytes, blastocysts, and embryonic and adult stem cells, we obtained 249,200 high-quality EST sequences and clustered them with public sequences to produce an index of approximately 30,000 total mouse genes that includes 977 previously unidentified genes. Analysis of gene expression levels by EST frequency identifies genes that characterize preimplantation embryos, embryonic stem cells, and adult stem cells, thus providing potential markers as well as clues to the functional features of these cells. Principal component analysis identified a set of 88 genes whose average expression levels decrease from oocytes to blastocysts, stem cells, postimplantation embryos, and finally to newborn tissues. This can be a first step towards a possible definition of a molecular scale of cellular potency. The sequences and cDNA clones recovered in this work provide a comprehensive resource for genes functioning in early mouse embryos and stem cells. The nonrestricted community access to the resource can accelerate a wide range of research, particularly in reproductive and regenerative medicine.

Molecular analysis of LPIN1 in Jordanian patients with rhabdomyolysis.

Recessive mutations in LPIN1, which encodes a phosphatidate phosphatase enzyme, are a frequent cause of severe rhabdomyolysis in childhood. Hence, we sequenced the 19 coding exons of the gene in eight patients with recurrent hereditary myoglobinuria from four unrelated families in Jordan. The long-term goal is to facilitate molecular genetic diagnosis without the need for invasive procedures such as muscle biopsies. Three different mutations were detected, including the novel missense mutation c.2395G>C (Gly799Arg), which was found in two families. The two other mutations, c.2174G>A (Arg725His) and c.1162C>T (Arg388X), have been previously identified, and were found to cosegregate with the disease phenotype in the other two families. Intriguingly, patients homozygous for Arg725His were also homozygous for the c.1828C>T (Pro610Ser) polymorphism, and were exercise-intolerant between myoglobinuria episodes. Notably, patients homozygous for Arg388X were also homozygous for the c.2250G>C silent variant (Gly750Gly). Taken together, the data provide family-based evidence linking hereditary myoglobinuria to pathogenic variations in the C-terminal lipin domain of the enzyme. This finding highlights the functional significance of this domain in the absence of structural information. This is the first analysis of LPIN1 in myoglobinuria patients of Jordanian origin, and the fourth such analysis worldwide.

Hereditary angioedema in a Jordanian family with a novel missense mutation in the C1-inhibitor N-terminal domain.

Hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE) is an autosomal dominant disease caused by mutations in the SERPING1 gene. A Jordanian family, including 14 individuals with C1-INH-HAE clinical symptoms, was studied. In the propositus and his parents, SERPING1 had four mutations leading to amino acid substitutions. Two are known polymorphic variants (c.167T>C; p.Val34Ala and c.1438G>A; p.Val458Met), the others are newly described. One (c.203C>T; p.Thr46Ile) is located in the N-terminal domain of the C1-inhibitor protein and segregates with angioedema symptoms in the family. The other (c.800C>T; p.Ala245Val) belongs to the serpin domain, and derives from the unaffected father. DNA from additional 24 family members were screened for c.203C>T mutation in the target gene. All individuals heterozygous for the c.203C>T mutation had antigenic and functional plasma levels of C1-inhibitor below 50% of normal, confirming the diagnosis of type I C1-INH-HAE. Angioedema symptoms were present in 14 of 16 subjects carrier for the c.203T allele. Among these subjects, those carrying the c.800T variation had more severe and frequent symptoms than subjects without this mutation. This family-based study provides the first evidence that multiple amino acid substitutions in SERPING1 could influence C1-INH-HAE phenotype.

Genomic organization and promoter regulation of human cytochrome c oxidase subunit VII heart/muscle isoform (COX7AH).

We have isolated and characterized the human gene (COX7AH) for the contractile muscle isoform of cytochrome c oxidase (COX) subunit VIIa. This subunit is one of the 10 nuclear encoded subunits of the 13-subunit holoenzyme that carries out the terminal step in the electron transport chain. Using transient transfection assays, we have located a 5'-flanking region sufficient to direct high level, skeletal myotube-specific reporter gene expression. This 792 bp basal promoter, which contains the single transcription start but no canonical TATA or CCAAT boxes, contains one MEF2 site, three E boxes, and an Sp1 site that show binding to their cognate factors, and are all required for full expression. Mutation and transactivation analysis suggest that there is functional interaction between these binding sites.

Two novel mutations of FBN1 in Jordanian patients with Marfan syndrome.

Marfan syndrome is an autosomal dominant inheritance disorder with a 1/5000-live-birth prevalence. More than 3000 mutations have been characterized thus far in the FBN1 gene. The goal of this study is to facilitate Marfan syndrome diagnosis in Jordanian patients using a molecular genetic testing. All of the 65 coding exons and flanking intronic sequences of the FBN1 gene were amplified using polymerase chain reaction and were subjected to sequencing in five unrelated Jordanian patients suspected of having Marfan syndrome. Four different mutations were identified, including two novel mutations: the c.1553dupG frame-shift (p.Tyr519Ilefs*14) and the c.6650G>A (p.Cys2217Tyr) missense mutations. Two other missense mutations, c.2243G>A (p.Cys748Tyr) and c.2432G>A (p.Cys811Tyr), have been previously detected. Patient number five was heterozygous for the synonymous substitution variant c.1875T>C (p.Asn625Asn; rs#25458). Additionally, eight variants in the intronic sequence of the FBN1 gene were identified, of which the c.2168-46A>G mutation was a new variant. The data provide molecular-based evidence linking Marfan syndrome to pathogenic mutations in the FBN1 gene among Jordanians for the first time. Thus, our results will contribute to the better management of the disease using molecular tools and will help in genetic counseling of the patients' families.

Analysis of JAK2V617F mutation in Jordanian patients with myeloproliferative neoplasms.

OBJECTIVE/BACKGROUND: Myeloproliferative neoplasms (MPNs) are heterogeneous clonal bone marrow stem cell disorders and include polycythemia vera (PV), essential thrombocythemia (ET), and idiopathic myelofibrosis (IMF) neoplasia. In 2005, the JAK2(V617F) mutation was identified in Philadelphia chromosome-negative patients. The aim of this study was to sequence coding exons 12 and 14 of the JAK2 gene in Jordanian patients with MPN. METHODS: Both exons 12 and 14 of the JAK2 gene were amplified using polymerase chain reaction from DNA extracted from 68 blood and bone marrow samples belonging to 57 MPN patients and subjected to DNA sequencing. RESULTS: JAK2(V617F) mutations were detected in 26 of 57 Jordanian patients (45%) with different MPNs. JAK2(V617F) was identified in 70%, 31%, and 14% of PV, ET, and IMF cases, respectively. Five men diagnosed with PV were homozygous for JAK2(V617F), whereas the other 21 patients were heterozygous for the mutation. Neither the JAK2(V617F) mutation nor any DNA polymorphism in exon 12 or exon 14 of the JAK2 gene was detected among the 40 leukemic patients. A rare single nucleotide polymorphism, c.1860C→T (rs375442615), was detected in one patient with ET. CONCLUSION: This study is the first molecular investigation of the JAK2 gene in Jordan. We successfully identified the JAK2(V617F) mutation in Jordanian patients with Philadelphia chromosome-negative MPNs. Our results provide a basis for the early detection of this mutation and simplify the diagnostic workup for these disorders at the molecular level.

Methoxyphenylcipro induces antitumor activity in human cancer cells.

To examine the antitumor activity of a new derivative of ciprofloxacin called methoxyphenylcipro (CMPP). Cell viability was assessed using the MTT assay and apoptotic cells and reactive oxygen species were evaluated using flow cytometry. Results revealed that CMPP induces antiproliferative activity against breast cancer cells and melanoma and to a lesser extent against colorectal cancer cells. Interestingly, compared to ciprofloxacin, CMPP-induced a selective cytotoxicity against human cancer cells but not human normal fibroblasts. The potential of CMPP to inhibit cellular growth in MD-MB-486 breast cancer cells and MV3 melanoma cells was largely due to induction of caspase-dependent apoptosis, as confirmed by caspase-3 activation and cleavage of its substrate PARP. In addition, results indicated that CMPP-induced apoptosis is mediated by generation of reactive oxygen species. These findings revealed that CMPP has a selective antitumor activity against cancer cells and warrants further clinical evaluation.

Custom genotyping for substance addiction susceptibility genes in Jordanians of Arab descent.

BACKGROUND: Both environmental and genetic factors contribute to individual susceptibility to initiation of substance use and vulnerability to addiction. Determining genetic risk factors can make an important contribution to understanding the processes leading to addiction. In order to identify gene(s) and mechanisms associated with substance addiction, a custom platform array search for a genetic association in a case/control of homogenous Jordanian Arab population was undertaken. Patients meeting the DSM-VI criteria for substance dependence (n = 220) and entering eight week treatment program at two Jordanian Drug Rehabilitation Centres were genotyped. In addition, 240 healthy controls were also genotyped. The sequenom MassARRAY system (iPLEX GOLD) was used to genotype 49 single nucleotide polymorphisms (SNPs) within 8 genes (DRD1, DRD2, DRD3, DRD4, DRD5, BDNF, SLC6A3 and COMT). RESULTS: This study revealed six new associations involving SNPs within DRD2 gene on chromosome 11. These six SNPs within the DRD2 were found to be most strongly associated with substance addiction in the Jordanian Arabic sample. The strongest statistical evidence for these new association signals were from rs1799732 in the C/-C promoter and rs1125394 in A/G intron 1 regions of DRD2, with the overall estimate of effects returning an odds ratio of 3.37 (χ2 (2, N = 460) = 21, p-value = 0.000026) and 1.78 (χ2 (2, N = 460) = 8, p-value = 0.001), respectively. It has been suggested that DRD2, dopamine receptor D2, plays an important role in dopamine secretion and the signal pathways of dopaminergic reward and drug addiction. CONCLUSION: This study is the first to show a genetic link to substance addiction in a Jordanian population of Arab descent. These findings may contribute to our understanding of drug addiction mechanisms in Middle Eastern populations and how to manage or dictate therapy for individuals. Comparative analysis with different ethnic groups could assist further improving our understanding of these mechanisms.