Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The distribution of the human liver alcohol dehydrogenase, ADH2, and aldehyde dehydrogenase, ALDH2, genotypes in 21 different populations comprising Mongoloids, Caucasoids, and Negroids was determined by hybridization of the amplified genomic DNA with allele-specific oligonucleotide probes. Whereas the frequency of the ADH1(2) allele was found to be relatively high in the Caucasoids, Mexican Mestizos, Brazilian Indios, Swedish Lapps, Papua New Guineans and Negroids, the frequency of the ADH2(2) gene was considerably higher in the Mongoloids and Australian Aborigines. The atypical ALDH2 gene (ALDH2(2)) was found to be extremely rare in Caucasoids, Negroids, Papua New Guineans, Australian Aborigines and Aurocanians (South Chile). In contrast, this mutant gene was found to be widely prevalent among the Mongoloids. Individuals possessing the abnormal ALDH2 gene show alcohol-related sensitivity responses (e.g. facial flushing), have the tendency not to be habitual drinkers, and apparently suffer less from alcoholism and alcohol-related liver disease.
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PMID:Distribution of ADH2 and ALDH2 genotypes in different populations. 173 36

A study was performed to verify that the prevalence of alcohol abuse and dependence in Formosan aborigines differs from that of Taiwanese (Chinese Han people), using analysis of aldehyde dehydrogenase (ALDH) isozymes and flush patterns on randomly sampled 70 Atayal, 66 Paiwan, 61 Yami and 94 Taiwanese subjects were studied. The activity of an isomer of ALDH having a low Km (ALDH-I) in hair roots was analysed by isoelectric focusing assay. The subjective experience of flushing response after alcohol ingestion was assessed. Results showed that the rate of ALDH-I deficiency in Taiwanese (51.1%) was significantly higher than in aborigines, i.e., 6.4%, 3.9%, and 0% in Atayal, Paiwan, and Yami subjects, respectively. The percentage occurrence of ALDH-I deficiency and prevalence of alcohol dependence in Taiwanese and aborigines were negatively correlated. The predominant pattern of self-reported flush response after alcohol use among aborigines was of slow onset. The flush response to alcohol ingestion was examined in relation to aldehyde metabolizing enzyme. Since alcohol sensitivity is an important factor in the development and maintenance of the alcohol ingestion habit in humans, our results support the hypothesis that there is a biological basis in the different rates of alcohol abuse and dependence among different ethnic groups.
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PMID:Aldehyde dehydrogenase deficiency, flush patterns and prevalence of alcoholism: an interethnic comparison. 178 Dec 98

Human ethanol consumption has a profound impact on nutritional status, causing major alterations in intermediary metabolism and critical deficiencies of vitamins and trace elements. The major enzyme systems responsible for the principal steps in ethanol metabolism have been characterized and the genes cloned, and significant functional polymorphisms have been identified. An inactive allele of the mitochondrial ALDH is associated with flushing and reduced alcohol intake. This allele may also confer greater sensitivity to some of ethanol's toxic effects. In populations not possessing this variant, twin and adoptive studies have revealed that heritability for alcoholism is greater than 50%. The occurrence of three functional polymorphisms in the ethanol metabolic pathway, including two mutations which are conserved across populations, suggests a role for selection in their maintenance. The two general categories of selective forces to maintain these polymorphisms are food toxins and infectious diseases. Of the infectious agents, amoebi and other anaerobic and microaerophilic organisms of the gut are the most logical candidates.
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PMID:Genetic epidemiology of ethanol metabolic enzymes: a role for selection. 219 94

In an earlier project, we identified five alcohol-consumption aftereffect factors, which were named Hangover, Euphoria, Flushing, Seizures, and Sleepiness. In this study (N = 100) we assessed the construct validities of the five, using 47 MMPI, self-report, and recidivism criteria. The number of significant relationships between the factors and the criteria substantially exceeded chance. The Hangover factor related to social maladjustment and to the MMPI Psychopathic Deviate, Paranoia, Psychasthenia, Hypomania, and Masculinity-Femininity scales. The Euphoria factor was associated with a high number of job losses, but a low incidence of certain physical sequelae. The Flushing factor was associated with high consumption, late development of alcoholism, many physical complaints, and older age. The Seizure factor correlated with high consumption, facial puffiness, tremors, and lack of defensiveness on the MMPI. The Sleepiness factor was associated with a good prognosis and several mild MMPI elevations. These findings suggest that the factors may provide the basis for a useful alcoholism subtyping system and that additional research on them should prove fruitful.
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PMID:The construct validity of an aftereffect-based subtyping system for alcoholics. 221 56

Inherited deficiency of acetaldehyde dehydrogenase type I (ALDH-I) was found in 43% (50/117) of normals, 33% (27/82) of schizophrenics, but only 4% (5/113) of alcoholics among Japanese. The ALDH-I deficiency was never found, however, in 146 mostly schizophrenic subjects from Europe (Basel, Moscow, Zagreb), Australia (Nedlands), India (Lucknow), Morocco (Casablanca) and Mexico (Mexico City). It was demonstrated that ALDH-I deficiency produces the flushing syndrome which inhibits the development of drinking habit and alcohol dependence syndrome.
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PMID:Biological study of alcohol dependence syndrome with reference to ethnic difference: report of a WHO Collaborative Study. 236 95

Research into the causes of alcoholism is a relatively recent scientific endeavor. One area of study which could lead to better understanding of the disease is the possibility of a genetic predisposition to alcoholism. Recent work has demonstrated that people have varying complements of enzymes to metabolize alcohol. Current knowledge is examined about the influence of various ethanol metabolizing enzymes on alcohol consumption by Asians and members of other ethnic groups. The two principal enzymes involved in ethanol oxidative metabolism are alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). ADH is responsible for the metabolism of ethanol to acetaldehyde. ALDH catalyzes the conversion of acetaldehyde to acetate. The different isozymes account for the diversity of alcohol metabolism among individuals. An isozyme of ADH (beta 2 beta 2) is found more frequently in Asians than in whites, and an ALDH isozyme (ALDH2), although present in Asians, often is in an inactive form. The presence of an inactive form of ALDH2 is thought to be responsible for an increase in acetaldehyde levels in the body. Acetaldehyde is considered responsible for the facial flushing reaction often observed among Asians who have consumed alcohol. A dysphoric reaction to alcohol, producing uncomfortable sensations, is believed to be a response to deter further consumption. Although the presence of an inactive ALDH2 isozyme may serve as a deterrent to alcohol consumption, its presence does not fully explain the levels of alcohol consumption by those with the inactive isozyme. Other conditions, such as social pressure, and yet undetermined biological factors, may play a significant role in alcohol consumption.
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PMID:Research on alcohol metabolism among Asians and its implications for understanding causes of alcoholism. 251 95

This study examined the skin-flushing response in Asian men, which is a low-risk factor for alcoholism. Asian men who did and did not flush to alcohol consumed 0.5 g/kg ethanol during three sessions with alcohol, and placebo in a fourth session. The results indicated that: (a) Asian men who flushed to alcohol showed pronounced cardiovascular changes that did not exhibit differential tolerance over 3 sessions, (b) there were surprisingly few self-reported mood differences in response to alcohol between those who did and did not flush, and (c) finger-pulse amplitude decreased and self-ratings of "boastful" increased significantly in response to placebo challenge in those men who did not flush. These results raise questions about the psychological mechanisms by which the skin-flushing response inhibits the development and expression of alcoholism.
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PMID:The skin-flushing response: autonomic, self-report, and conditioned responses to repeated administrations of alcohol in Asian men. 259 76

The existence of racial differences in alcohol sensitivity between Oriental and Caucasian populations has been well documented. The primary manifestation is a highly visible facial flushing (47-85% in Orientals vs 3-29% in Caucasians) accompanied by other objective and subjective symptoms of discomfort. Even among different Oriental groups, subtle differences in the flushing response and alcohol consumption can exist. North and South American Indian populations differ in phenotypes for alcohol dehydrogenase and aldehyde dehydrogenase, but systematic studies comparing degree of flushing, alcohol elimination rates and blood acetaldehyde levels in these populations are lacking. Although flushing does not automatically 'immunize' an individual against alcohol use, those susceptible tend to consume less alcohol, at least in Orientals. However, the flushing phenomenon cannot be the sole explanation for differences in incidences of alcoholism among different racial groups. Socio-cultural, environmental and genetic factors also have to be considered. An increased incidence of flushing has been found to associate with a familial risk of development of future alcoholism in a Caucasian population. It remains to be determined whether the same is true in Orientals. Most biochemical investigations of the flushing phenomenon have focused on aspects of alcohol metabolism. Based on recent findings, a convincing mechanism is the higher accumulation of acetaldehyde in flushing subjects because they have an unusual, less-active liver aldehyde dehydrogenase isozyme (ALDHI). The possibility that an 'atypical' alcohol dehydrogenase, which is present in 85-90% of Oriental subjects, can contribute to increased blood acetaldehyde levels in flushing subjects cannot be ruled out. Based on results of a small number of pedigree studies which demonstrated familial resemblances in flushing, a pharmacogenetic defect in ALDHI has been proposed to be responsible for flushing. Other possible biochemical mechanisms (e.g. prostaglandins) and genetic defects need to be investigated.
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PMID:Racial differences in alcohol sensitivity. 293 17

Differences in the pharmacokinetics of alcohol absorption and elimination are, in part, genetically determined. There are polymorphic variants of the two main enzymes responsible for ethanol oxidation in liver, alcohol dehydrogenase and aldehyde dehydrogenase. The frequency of occurrence of these variants, which have been shown to display strikingly different catalytic properties, differs among different racial populations. Since the activity of alcohol dehydrogenase in liver is a rate-limiting factor for ethanol metabolism in experimental animals, it is likely that the type and content of the polymorphic isoenzyme subunit encoded at ADH2, beta-subunit, and at ADH3, the gamma-subunit, are contributing factors to the genetic variability in ethanol elimination rate. The recent development of methods for genotyping individuals at these loci using white cell DNA will allow us to test this hypothesis as well as any relationship between ADH genotype and the susceptibility to alcoholism or alcohol-related pathology. A polymorphic variant of human liver mitochondrial aldehyde dehydrogenase, ADLH2, which has little or no acetaldehyde oxidizing activity has been identified. Individuals with the deficient ALDH2 phenotype do not have altered ethanol elimination rates but they do exhibit high blood acetaldehyde levels and dysphoric symptoms such as facial flushing, nausea and tachycardia, after drinking alcohol. Because acetaldehyde is so reactive, it binds to free amino groups of proteins including a 37 kilodalton hepatic protein-acetaldehyde adduct and may elicit an antibody response. We would predict that individuals who have low ALDH2 activity because of liver disease or because they have the inactive ALDH2 variant isoenzyme might form more protein-acetaldehyde adducts and elicit a greater immune response. These adducts may represent good biological markers of alcohol abuse and may also play a role in liver injury due to chronic alcohol consumption.
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PMID:Genetic polymorphism of enzymes of alcohol metabolism and susceptibility to alcoholic liver disease. 306 25

The metabolism of acetaldehyde has received considerable attention in the past years owing to its acute and chronic toxic effects in humans. Aldehyde dehydrogenase (ALDH) catalyzes the oxidation of acetaldehyde in liver and other organs. Two major isozymes of hepatic ALDH (ALDH I or E2 and ALDH II or E1), which differ in their structural and functional properties, have been characterized in humans. The ALDH I with a low Km for acetaldehyde is predominantly of mitochondrial origin and ALDH II which has a relatively higher Km is of cytosolic origin. An inherited deficiency of ALDH I isozyme has been found among Japanese and Chinese which is primarily responsible for producing acute alcohol sensitivity symptoms (flushing response) after drinking mild doses of alcohol. Biochemical, immunochemical and molecular genetics data indicate a structural mutation in the ALDH I isozyme gene responsible for the loss in catalytic activity. Population genetic studies indicate a wide prevalence of this ALDH polymorphism among individuals of Mongoloid race. Flushing response to alcohol shows familial resemblances and preliminary family data from Japan, China and Korea hint to an autosomal codominant inheritance for ALDH I isozyme deficiency. The ALDH polymorphism is apparently responsible for the low incidence of alcoholism in Japanese, Chinese and Koreans. Alcohol-induced sensitivity due to ALDH isozyme deficiency may act as an inhibitory factor against excessive alcohol drinking thereby imparting a protection against alcoholism.
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PMID:Polymorphism of aldehyde dehydrogenase and alcohol sensitivity. 310 30


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