Strong and weak cross-inheritance of substance use disorders in a nationally representative sample.

Substance use disorders (SUDs) are moderately to highly heritable and are in part cross-transmitted genetically, as observed in twin and family studies. We performed exome-focused genotyping to examine the cross-transmission of four SUDs: alcohol use disorder (AUD, n = 4487); nicotine use disorder (NUD, n = 4394); cannabis use disorder (CUD, n = 954); and nonmedical prescription opioid use disorder (NMPOUD, n = 346) within a large nationally representative sample (n = 36,309), the National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III). All diagnoses were based on in-person structured psychiatric interview (AUDADIS-5). SUD cases were compared alone and together to 3959 "super controls" who had neither a SUD nor a psychiatric disorder using an exome-focused array assaying 363,496 SNPs, yielding a representative view of within-disorder and cross-disorder genetic influences on SUDs. The 29 top susceptibility genes for one or more SUDs overlapped highly with genes previously implicated by GWAS of SUD. Polygenic scores (PGS) were computed within the European ancestry (EA) component of the sample (n = 12,505) using summary statistics from each of four clinically distinct SUDs compared to the 3959 "super controls" but then used for two distinctly different purposes: to predict SUD severity (mild, moderate, or severe) and to predict each of the other 3 SUDs. Our findings based on PGS highlight shared and unshared genetic contributions to the pathogenesis of SUDs, confirming the strong cross-inheritance of AUD and NUD as well as the distinctiveness of inheritance of opioid use disorder.

Butyrylcholinesterase (BChE) activity is associated with the risk of preeclampsia: influence on lipid and lipoprotein metabolism and oxidative stress.

OBJECTIVE: To determine the butyrylcholinesterase (BChE) activity and phenotypes in preeclampsia and its possible association with lipid and lipoprotein metabolism and oxidative stress in preeclamptic women. METHODS: In a case-control study, 101 pregnant women with normal pregnancy and 198 women with preeclampsia from Western Iran were studied. The serum BChE activity and phenotypes were measured using spectrophotometric method. The apolipoprotein E (APOE) genotypes were identified using PCR-RFLP. The serum malondialdehyde (MDA) level and total antioxidant capacity (TAC) were determined by HPLC and commercial kits, respectively. RESULTS: The BChE activity and the frequency of non-usual BChE phenotype in preeclamptic women were significantly lower and higher, respectively compared to controls. There was a higher BChE activity in the presence of APOE ε3ε4 compared to ε3ε3 genotype in preeclamptic women. In addition, there were significant positive correlations between BChE activity and the levels of low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, total cholesterol (TC) and TAC. However, there was a negative but significant correlation between BChE activity and MDA level. CONCLUSIONS: Our study for the first time indicated that BChE activity might be involved in the pathogenesis of preeclampsia through influence on lipid and lipoprotein metabolism and oxidative stress.

Preeclampsia and angiotensin converting enzyme (ACE) I/D and angiotensin II type-1 receptor (AT1R) A1166C polymorphisms: association with ACE I/D polymorphism.

BACKGROUND: The aim of the present study was to investigate the association between angiotensin converting enzyme (ACE) insertion/deletion (I/D) and angiotensin II type-1 receptor (AT1R) A1166C polymorphisms with the risk of preeclampsia and lipid peroxidation in preeclamptic women from Western Iran. METHODS: One hundred and ninety-eight preeclamptic women (128 women with mild and 70 with severe forms) and 100 age- and parity-matched controls were enrolled in this case-control study. RESULTS: The presence of D allele of ACE was associated with a 1.8-fold increased risk of preeclampsia (p=0.002) in total preeclamptic patients. The frequency of AT1R AC+CC genotypes was higher in mild preeclamptic women (32%) compared to controls (27.2%) (p>0.05). In mild preeclamptic women with ID genotype, the level of total antioxidant capacity (TAC) was significantly decreased compared to those with II genotype. Also, there was a trend toward increasing malondialdehyde (MDA) and decreasing TAC levels in mild and severe preeclamptic women with AT1R AA through CC genotypes. CONCLUSIONS: Our study indicates that lipid peroxidation and oxidative stress are involved in the development of preeclampsia that might be influenced by polymorphism in the renin-angiotensin-aldosterone system genes.

MTHFR C677T and eNOS G894T variants in preeclamptic women: Contribution to lipid peroxidation and oxidative stress.

OBJECTIVES: We aimed to investigate the association between methylenetetrahydrofolate reductase (MTHFR) C677T and endothelial nitric oxide synthase (eNOS) G894T polymorphisms with lipid peroxidation, total antioxidant capacity (TAC) and the risk of preeclampsia in preeclamptic women. DESIGN AND METHODS: We screened a sample of 198 unrelated women with mild and severe forms of preeclampsia and 101 unrelated women with normal pregnancy with the eNOS and MTHFR variants using PCR-RFLP method. Also, the serum malondialdehyde (MDA) and TAC levels were determined using HPLC and commercial kits, respectively. RESULTS: The frequency of combined genotypes of MTHFR CT and TT (CT+TT) and T allele tended to be higher in severe preeclamptic women compared to controls. There was no significant difference for eNOS G894T genotype and allele frequencies between patients and controls. A significantly higher level of triglycerides was observed in the presence of combined genotypes of MTHFR CT and TT and also eNOS GT and TT (GT+TT) in preeclamptic women compared to controls with the same genotype. Also, the presence of MTHFR TT genotype in severe preeclamptic women was significantly associated with the increased serum MDA level compared to CC genotype. In severe preeclamptic women the presence of CT and combined genotypes of CT and TT was significantly associated with the decreased TAC level compared to CC genotype. Also, a higher MDA level was observed in mild preeclamptic women with eNOS TT genotype compared to those with GG genotype but the difference was not significant. CONCLUSION: The present study indicates that MTHFR C677T polymorphism through affecting on TG level, lipid peroxidation and oxidative stress might be involved in the pathogenesis of severe preeclampsia.

Strong interaction between T allele of endothelial nitric oxide synthase with B1 allele of cholesteryl ester transfer protein TaqIB highly elevates the risk of coronary artery disease and type 2 diabetes mellitus.

BACKGROUND: The present study was conducted to investigate the possible outcome of interaction between endothelial nitric oxide (NOS3) G894T and cholesteryl ester transfer TaqIB variants on the risk of coronary artery disease (CAD) and type 2 diabetes mellitus (T2DM). The sample included a total of 207 CAD patients (102 CAD patients with T2DM and 105 CAD patients without T2DM). There were also 101 patients with T2DM and 92 age- and sex-matched healthy individuals as controls. All study participants were from Western Iran. The sample was genotyped by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: The presence of NOS3 T allele was not associated with the risk of CAD or T2DM, and the CETP B1 allele was only significantly associated with the increased risk of CAD in total CAD patients (odds ratio (OR) = 5.1, p = 0.019). However, the concomitant presence of both CETP B1 and NOS3 T alleles significantly increased the risk of CAD in total CAD patients (OR = 18.1, p < 0.001), in CAD patients without T2DM (OR = 27.1, p = 0.03), and in CAD patients with T2DM (OR = 13.5, p = 0.002). Also, the presence of both alleles increased the risk of T2DM (OR = 12, p = 0.004). CONCLUSIONS: Our findings, for the first time, indicate that NOS3 T allele strongly interacts with CETP B1 allele to augment the risk of CAD and T2DM in the population of Western Iran.

Thymidylate synthase and methionine synthase polymorphisms are not associated with susceptibility to childhood acute lymphoblastic leukemia in Kurdish population from Western Iran.

In order to determine the influence of polymorphism in thymidylate synthase (TS 28-bp repeat) and methionine synthase (MS A2756G) genes on the susceptibility to acute lymphoblastic leukemia (ALL), 73 children with ALL and 128 age and sex matched unrelated healthy individuals from the Kermanshah Province of Iran were screened. The genotyping of TS 28-bp repeat and MS A2756G polymorphisms were performed by polymerase chain reaction (PCR) and PCR-RFLP, respectively. The frequency of TS 2R allele in patients and controls were 41.5 and 38%, respectively (Odds ratios (OR) = 1.13, 95%CI 0.73-1.74, P = 0.56). The allelic frequency of G allele of MS was higher (25%) in patients compared with healthy subjects (23%) (OR = 1.09, 95%CI 0.67-1.75, P = 0.71). Considering MS AA and TS 3R3R genotypes as reference indicated that individuals with MS GG + TS 2R2R genotypes have 1.3-fold increase in the risk of ALL (OR = 1.3, 95%CI 0.6-2.7, P = 0.5). Our results showed that neither TS 28-bp repeat nor MS A2756G polymorphisms are risk factors for susceptibility to ALL in Western Iran.

Lack of association between MTHFR C677T and A1298C polymorphisms and risk of childhood acute lymphoblastic leukemia in the Kurdish population from Western Iran.

AIMS: Polymorphism in genes involved in folate metabolism may influence the susceptibility to acute lymphoblastic leukemia (ALL). The aim of the present study was to determine the role of the two most common polymorphisms of the 5, 10-methylenetetrahydrofolate reductase (MTHFR) gene, MTHFR C677T and A1298C, and their interaction on the susceptibility to ALL. METHODS: Seventy-two children with ALL and 109 age- and sex-matched healthy children from Western Iran were screened for MTHFR C677T and A1298C variants by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: The frequencies of MTHFR 677T and 1298C alleles in patients were 29.9% and 43.1%, respectively, that were higher than those in controls (24.8% and 38.1%, respectively). Logistic regression analysis was performed and its result in the odds ratios (ORs) for possession of either MTHFR 677T or 1298C allele was found to be 1.98 [95% confidence interval (CI) 0.72-5.4, p = 0.18] and 1.48 (95% CI 0.59-3.69, p = 0.4), respectively. Also the concomitant presence of both MTHFR 677T and 1298C alleles was not associated with the risk of ALL [OR = 2.12 (95% CI 0.8-5.7, p = 0.13)]. CONCLUSION: Our results in a homogenous population with Kurdish ethnic background indicated that neither the MTHFR 677T allele nor the MTHFR 1298C allele is associated with increased risk of ALL.

Concomitant presence of endothelial nitric oxide 894T and angiotensin II-converting enzyme D alleles are associated with diabetic nephropathy in a Kurdish population from Western Iran.

AIM: The present study investigated the influence of insertion (I)/deletion (D) polymorphism of the angiotensin II-converting enzyme (ACE) gene in combination with endothelial nitric oxide (eNOS) G894T polymorphism on the predisposition to diabetic nephropathy (DN). METHODS: Using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP) method, the ACE and eNOS polymorphisms were genotyped in 72 microalbuminuric, 68 macroalbuminuric and 72 normoalbuinuric type 2 diabetes mellitus (T2DM) patients from Western Iran. RESULTS: The presence of eNOS T or ACE D allele was not associated with increased risk of macroalbuminuria (odds ratio (OR) = 1.36, P = 0.27 and OR = 1.6, P = 0.062, respectively). However, in the presence of both alleles there was a trend towards increased risk of macroalbuminuria (fivefold, P = 0.05). CONCLUSION: Our study indicates that the concomitant presence of both ACE D and eNOS T alleles tends to be associated with an elevation risk of macroalbuminuria compared with the presence of each polymorphism alone. This risk could be attributed to the increasing activity of ACE and angiotensin II level in the presence of D allele and decreasing NO production in the presence of T allele accelerating diabetic nephropathy.

Thrombophilic mutations and susceptibility to preeclampsia in Western Iran.

The aim of the present study was to investigate the frequency and the possible association between thrombophilic mutations of factor V Leiden (FVL) and prothrombin G20210A with preeclampsia among Kurdish population of Western Iran. We studied 198 women with preeclampsia including 128 women with mild and 70 women with severe forms and 101 healthy pregnant women with uncomplicated pregnancy. Among cases there were 23 women with early onset preeclampsia and 175 cases with late-onset preeclampsia. The sample was genotyped by polymerase chain reaction-restriction fragment-length polymorphism using Mnl I and Hind III for FVL and prothrombin G20210A, respectively. The frequency of heterozygous FVL mutation was 7.6% among all preeclamptic women (8.6% in mild and 5.7% in severe preeclamptic women) and 7.9% in controls (P > 0.05). However, the prevalence of heterozygous FVL were 10.5 and 3.9% among severe preeclamptic women with early onset and late-onset preeclampsia, respectively (P > 0.05). The prevalence of prothrombin G20210A were 1.6, 2.9, and 3% among women with mild preeclamsia, severe preeclampsia and controls, respectively (P > 0.05). The level of serum triglycerides (TG) was significantly higher among women with preeclampsia compared to healthy pregnant women that was not associated with the two thrombophilic mutations. Our results indicate that neither FVL nor prothrombin G20210A could be a risk factor for preeclampsia in our population. However, high prevalence of FVL in preeclamptic women with early onset compared to those with late-onset preeclampsia may suggest a role for this mutation in predisposition to early onset preeclampsia that need to be confirmed with larger sample size.

Sickle cell disease and venous thromboembolism.

Hemoglobin S in homozygous state or in combination with one of the structural variants of Hb D-Punjab, Hb O-Arab, Hb C or ß-thalassemia mutation results in sickle cell disease (SCD) that is characterized by chronic hemolytic anemia and tissue injury secondary to vasooclusion. A chronic hypercoagulable state in SCD has been established with the increased risk of thromboembolic complications in these patients. The goal of present review is to survey of the literature related to thromboembolic events and genetic risk factors involved in the manifestation of these events in SCD patients with focus on studies from Mediterranean countries. Also, this review covers the pathogenesis of hypercoagulability and alteration in the components of hemostasis system.

Association between cholesteryl ester transfer protein TaqIB variants and risk of coronary artery disease and diabetes mellitus in the population of western Iran.

AIMS: To shed light on the previously inconsistent results about the association of cholesteryl ester transfer protein TaqIB (CETP TaqIB) variants, high-density lipoprotein cholesterol (HDL-C) levels, and the risk of coronary artery disease (CAD) and type 2 diabetes mellitus (T2DM). METHODS: To determine the frequency of CETP TaqIB variants and to examine the possible association between CETP TaqIB polymorphism with CAD and T2DM, we studied 207 unrelated patients with CAD, 101 patients with T2DM, and 92 controls. The CETP TaqIB variants were detected by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: Logistic regression analysis indicated that the B1 allele of CETP was significantly associated with increased risk of CAD (odds ratio, OR 1.65 [95% confidence interval, CI 1.2-2.3, p=0.005]) and T2DM (OR 1.7 [95% CI 1.13-2.54, p=0.005]). Adjusted logistic regression analysis for the effects of age, sex, hypertension, diabetes, and hyperlipidemia was performed; and a significant association was found between the B1 allele and risk of CAD (OR 1.9 [95% CI 1-3.6, p=0.049]) in patients with CAD. There were no associations between the CETP alleles and the levels of triglycerides, total cholesterol, low-density lipoprotein cholesterol, and HDL-C in studied groups. CONCLUSIONS: The results of the present study revealed that the CETP B1 allele is associated with increased risk of CAD and T2DM independent of plasma HDL-C level in our population.

Plasma lipids and lipoproteins in children and young adults with major ß-thalassemia from western Iran: influence of genotype.

To determine the plasma lipid and lipoprotein profiles and their possible association with the type of ß-thalassemia mutation we studied 103 major ß-thalassemia patients including 71 children and 32 young adults compared to 102 healthy subjects consisted of 90 children and 12 young healthy adults. The plasma lipid and lipoprotein levels were measured by conventional methods. Considering all of the patients the levels of total cholesterol (TC), LDL-cholesterol (LDL-C), and HDL-cholesterol (HDL-C) were significantly lower compared to controls. However, the level of TG was significantly higher in cases than controls. Comparing thalassemic patients homozygous for a ß0 type of mutation with those homozygous for a ß+ type of mutation (IVSI.110 G:A) indicated that the levels of LDL-C, TC were significantly increased and TG concentration tended to be higher in the latter patients. In conclusion, our study indicates that hemolytic stress results in hypocholesterolemia in major ß-thalassemia patients and the presence of more severe genotype in patients is correlated with more reduction in TG, TC, and LDL-C levels.

Deep venous thrombosis and thrombophilic mutations in western Iran: association with factor V Leiden.

The aim of present study was to investigate the prevalence of factor V Leiden (FVL) c.1691G>A, prothrombin g.20210G>A and methylenetetrahydrofolate reductase (MTHFR) c.677C>T in deep vein thrombosis (DVT) patients and their possible association with DVT in western Iran. Eighty DVT patients with the mean age of 42.07 +/- 13.0 years including 44 women and 36 men and 100 sex-matched healthy individuals with the mean age of 37.63 +/- 13.3 years from Kermanshah Province of Iran with ethnic background of Kurd were studied for FVL c.1691G>A, prothrombin g.20210G>A and MTHFR c.677C>T by PCR-restriction fragment length polymorphism (RFLP) method using MnlI, HindIII and HinfI restriction enzymes, respectively. Prevalence of FVL was 11.4% in patients and 2% in control group. A significant association was found between FVL mutation and DVT with odds ratio (OR) of 6.3 [95% confidence interval (CI) = 1.32-30.05; P = 0.012]. The prevalence of prothrombin g.20210G>A variant in patients (3.8%) was nonsignificantly higher than control individuals (1.0%; OR 3.8; 95% CI = 0.39-37.81; P = 0.32). The prevalence of MTHFR c.677C>T in patients was 38.7% that was not statistically different from control group (44% P = 0.12). Venous thrombosis in legs was the most frequent clinical manifestation (n = 75), corresponding to 93.8% of the thromboembolism, followed by pulmonary thromboembolism (6.2%). We have, for the first time, determined the prevalence of inherited thrombophilia in a homogenous ethnic group of DVT patients and shown that FVL may be a risk factor for DVT in western Iran.

Detection of responsible mutations for beta thalassemia in the Kermanshah Province of Iran using PCR-based techniques.

Beta Thalassemia has been reported to be a common genetic disorder in Iran. To establish the molecular spectrum of the beta thalassemias in the Kermanshah Province of Iran, 185 unrelated beta thalassemia patients with Kurdish ethnic background were studied (181 beta-thalassemia major and 4 beta-thalassemia intermedia). Using polymerase chain reaction-amplification refractory mutation system (PCR-ARMS), restriction fragment length polymorphism (RFLP) and direct genomic sequencing twenty different mutations were identified accounting for 98.1% of the alleles. Approximately 80.8% of beta-thalassemia chromosomes had beta(0) mutation. The most prevalent mutation was the IVSII-1 (G-->A) (32.97%), followed by CD8/9 +G (13.51%), IVSI-110 (C-->T) (8.38%), CD 36/37 -T (7.84%), CD8 -AA (5.94%), CD15 (G-->A) (4.86%) and IVSI-1 (G-->A) (4.59%). All of these mutations accounted for 78.1% of the alleles. The results described here will be of valuable help in the development of successful prevention programs for the population of Kermanshah.

Factor V G1691A, prothrombin G20210A and methylenetetrahydrofolate reductase polymorphism C677T are not associated with coronary artery disease and type 2 diabetes mellitus in western Iran.

There are controversial results related to the contribution of factor V Leiden G1691A, prothrombin gene G20210A and methylentetrahydrofolate reductase (MTHFR) C677T mutations in the development of coronary artery disease (CAD) and their association with diabetes. To assess the distribution of these thrombophilic mutations in CAD patients with and without type 2 diabetes mellitus (T2DM), we studied 117 CAD patients [65 CAD patients with diabetes (CAD/T2DM) and 52 CAD patients without diabetes (CAD/ND)] and 59 age-matched and sex-matched healthy individuals without CAD from population of western Iran. Genotyping was done by polymerase chain reaction (PCR)-restriction fragment length polymorphism using Mnl I, Hind III and Hinf I for factor V Leiden, prothrombin G20210A and MTHFR C677T, respectively. The prevalence of prothrombin G20210A variant in CAD/T2DM, CAD/ND and control individuals was 3.1, 1.9 and 0%, respectively. Factor V Leiden G1691A was found in 4.6% of patients with CAD/T2DM, 3.8% of patients with CAD/ND and 3.4% of healthy individuals. The prevalence of MTHFR C677T was found to be 49.2, 32.7 and 44.1% in CAD/T2DM, CAD/ND and control group, respectively. Our results indicate that there is no significant difference between the prevalence of thrombophilic mutations of factor V Leiden, prothrombin G20210A variant and MTHFR C677T in CAD patients with or without diabetes compared with controls. Although a higher prevalence of these thrombophilic mutations was observed in CAD patients, especially in those patients with diabetes, it seems that these variants may not be considered as independent risk factors for CAD or diabetes in our sample. These findings are discussed in relation to available literature.

Haplotype analysis of beta thalassemia patients in Western Iran.

Beta-thalassemia (beta-thal) is the most common single gene disorder in Iran. To determine the chromosomal background of beta thalassemia mutations in Western Iran we studied beta-globin gene cluster haplotypes in 314 beta-thal and 70 beta(A) chromosomes with a Kurd ethnic background from the province of Kermanshah, Iran using PCR-RFLP. beta-thal mutations were analyzed using PCR-ARMS, RFLP and direct genomic sequencing. Haplotypes were constructed by analyzing the pattern of seven restriction sites through the beta-globin gene cluster. Haplotype I was the most prevalent haplotype (35.7%) among beta-thal chromosomes followed by haplotype III (28.6%). beta(A) chromosomes similar to beta-thal chromosomes were linked to diverse haplotypes but predominantly with haplotype I (42.9%). The predominant IVSII-1 (G-->A) mutation in this population (33%) was strongly linked to haplotype III (66.1%) but was also found on chromosomes with haplotypes I, II, V, X and atypical. The second prevalent mutation was CD8/9 +G (13.5%) and showed a strong association with haplotype I (96.4%) and a weak association with haplotype V (3.6%). Haplotype background for Kurdish mutations among our studied population was similar to those among Kurdish Jews and people of Kurdistan of Iran. Identification of the most common mutations on different haplotype backgrounds can be explained by a variety of gene conversion and recombination events.

LRRK2 gene G2019S mutation and SNPs [haplotypes] in subtypes of Parkinson's disease.

Mutation within the leucine-rich repeat kinase 2 (LRRK2) gene has been identified as a cause of autosomal dominant Parkinson's disease (PD). The purpose of this study was to determine the frequency of G2019S mutation and whether the differences in the allele and genotype distribution of six SNPs within LRRK2 gene are associated with PD in an American non-Hispanic white population. The sample included 350 sporadic PD (SPD), 225 familial PD (FPD) patients and 186 controls of the same race and ethnicity. The frequency of LRRK2 G2019S mutation in our total sample of PD (FPD and SPD) was 1.56%. The frequency of this mutation was 3.5% in the FPD and 0.3% in the SPD groups, respectively. Allele and genotype frequencies of six SNPs were compared between PD and control samples. In addition, PD groups were categorized by sporadic PD (no family history), familial PD (first degree relative with PD) and age of onset (AON, or=51years). The haplotypes of the six SNPs were also constructed for association analysis. After correction for multiple comparisons, there was no association between any SNPs (allele or genotype) and PD groups. One of the haplotypes was modestly associated with the combined PD (SPD and FPD) sample. There was also no association with age at onset of PD. Our study suggests that the LRRK2 gene may be a risk factor or the cause for a very small fraction of PD in American white population.

Further genetic characterization of the fawn-hooded (FH/Wjd) rat, an animal model of comorbid depression and alcoholism.

OBJECTIVE: The main objective of this study was a more detailed genetic characterization of the alcohol preferring fawn-hooded rat and its intercrosses. Fawn-hooded rats drink substantially more alcohol voluntarily than the ACI rats. The fawn-hooded rats were shown to be more immobile in the forced-swimming test and to drink more saccharin. Recent comparisons of the parental strains with F1 and F2 intercrosses revealed that the alcohol and saccharin intakes were positively correlated with each other but not with immobility. METHODS: The F1 and F2 progeny were generated by intercrossing the fawn-hooded and ACI/N rats. Data from the F2 progeny, their F1 parents and progenitors were used to estimate heritability. RESULTS: Heritability was estimated for alcohol intake (75.6% in males and 67.1% in females), alcohol preference (64.7% in males and 39.2% in females), saccharin intake (50.8% in males and 37.5% in females), and immobility (50.2% in males and 72.1% in females). This same data provided estimates of the number of genes involved in these phenotypes between three and six. We also took advantage of the fact that both progenitor strains are pigmented, so a tremendous variety of coat colors were present in the F2 progeny (i.e. black, black-hooded, agouti, agouti-hooded, fawn, fawn-hooded, orange, and orange-hooded). Coat color analyses indicated that none of the variables significantly varied with coat color. A high correlation however, was observed between alcohol intake and preference in each group. Significant correlations between alcohol and saccharin intakes were seen only in some groups. CONCLUSION: These findings suggest that these phenotypes might be regulated by multiple genes, which could be detected in quantitative trait loci. These analyses are currently underway and will provide a novel approach in understanding the genetics of voluntary alcohol drinking.

Analysis of alcohol-related phenotypes in F2 progeny derived from FH/Wjd and ACI/N rat strains reveals independent measures and sex differences.

Ethanol associated addictive behaviors are governed by a combination of multiple gene action (polygenic or quantitative trait) and environmental factors. We produced F2 progeny from F1 crosses derived from the alcohol-preferring Fawn-Hooded (FH/Wjd) rat strain and the alcohol-nonpreferring ACI/N strain. We compared different phenotypes related to alcohol intake in more than 600 F2 progeny. We found that female rats had significantly higher mean voluntary and forced ethanol, water, saccharin and total fluid intakes than male rats. Therefore, we compared these measures in the top 15th percentile with those in bottom 15th percentile of the F2 total ethanol intake distribution separately for males and females. The two tail comparison of means showed that only the trait of alcohol preference differed significantly in both males and females, suggesting that alcohol preference is closely related to alcohol intake. Because of the detailed information about the F1 parents of the F2 progeny, it was possible to determine parental effects. For swim test immobility, for example, the F2 progeny derived from FA(m)/FA(f) parents (ACI maternal inheritance) had the lowest mean value of 130s while the F2 progeny from AF/AF parents (FH maternal inheritance) had the highest mean value of 157s (p<0.005). The F2 progeny derived from FA/AF parents (FH maternal inheritance) showed higher mean values of forced alcohol intake than FA/FA parents (FH paternal inheritance) (6.58 and 6.36g/kg/day, respectively) suggesting that the FH mother had a significantly (p<0.0001) greater effect on forced alcohol intake than the FH father. It is concluded from these analyses that alcohol-related phenotypes are segregating independently and may be influenced by maternal and sex factors.

Depressive-like behavior and high alcohol drinking co-occur in the FH/WJD rat but appear to be under independent genetic control.

This review will consider the evidence supporting the view that a specific substrain of Fawn-Hooded rat (FH/Wjd) exhibits co-occurring depressive-like behavior and high alcohol intake independently. First, the FH/Wjd rat is compared with other Fawn-Hooded substrains (FH/Har, FHH/Eur, FHL/Eur) and it is concluded that only the FH/Wjd rat is both highly immobile in the forced swim test and drinks substantial amounts of 5-10% alcohol voluntarily. Next it is demonstrated that the FH/Wjd rat fulfils many of the criteria proposed for an animal model of alcoholism (becomes tolerant, becomes dependent and expresses withdrawal symptoms, bar-presses for alcohol). Other literature in addition to the high swim test immobility suggests that the FH/Wjd rat may also be an animal model of depression (high basal corticosterone levels, blunted hormonal responses to serotonergic agonists). To study the phenotypes more closely an inbred strain (ACI/N) of rat that drank little alcohol voluntarily and exhibited considerable swimming in the forced swim test (i.e., low immobility) was obtained. A systematic intercrossing of the parental strains and the resulting F1 progeny was carried out to generate more than 800 F2s. Swim test immobility, alcohol intake and preference and saccharin intake are four of the 7 variables assessed in each of these rats. Using classical quantitative genetics methods, it was determined that these four phenotypes exhibited modest heritability and were influenced by multiple genes. Correlation coefficients between immobility and the other measures were near zero, whereas alcohol intake and preference were highly correlated (r=0.9) and alcohol and saccharin intakes were modestly correlated (r=0.3). A final study showed that chronic fluoxetine treatment counteracted the high immobility but did not affect alcohol intake, similar to human studies. These findings suggest that although depressive-like behavior and high alcohol intake co-occur in the FH/Wjd rat, they are independently regulated.