Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.14.16.2 (tyrosine hydroxylase)
 14,760 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genetic linkage between manic depression and DNA markers on the short arm of chromosome 11 was first reported in 1987 but not supported by further analyses. However, genetic markers at the tyrosine hydroxylase (TH) gene located within this region have been reported to show allelic association with the affective disorder phenotype. We present the results of a linkage analysis using polymorphic DNA segments within the TH gene and the nearby dopamine D4 receptor (DRD4) gene in 6 families multiply affected with affective disorder. Small positive Lod scores were obtained in 2 of 6 pedigrees with the TH polymorphism which may be indicative of genetic heterogeneity.
 ...
PMID:Linkage between tyrosine hydroxylase gene and affective disorder cannot be excluded in two of six pedigrees. 790 43

The candidate genes tyrosine hydroxylase (TH) and the dopamine D4 receptor gene (DRD4) are both located in the 11p15.5 region, thus creating strong interest in this region for genetic studies of bipolar affective disorder. It is conceivable that disregulation of the dopamine system could arise from genetic defects in DRD4 or TH, which in turn may lead to susceptibility to this disorder. We have begun our search for an autosomal linkage to bipolar affective disorder in the Old Order Amish (OOA110) with the 48 bp coding region polymorphism for DRD4. A small positive lod score of 1.16 was determined. A new polymerase chain reaction-based tetranucleotide repeat marker for the TH gene was investigated, and also had a small positive lod score of 0.63 at theta = 0.10. This finding replicates the small positive (lod = 0.42) RFLP results of Pakstis et al, (1991a). These two new markers were not able to provide statistically significant results, however their role as modifier genes in the pathogenesis of affective disorders cannot be excluded. Future studies that include the sequence variants within the 48 bp motif of the DRD4 coding region polymorphism, and possibly alternate definitions of the affective disorder phenotype, may provide more definitive answers.
 ...
PMID:Analysis of new D4 dopamine receptor (DRD4) coding region variants and TH microsatellite in the Old Order Amish family (OOA110). 791 60

The dopamine D4 receptor gene and the closely placed tyrosine hydroxylase (TH) receptor gene are important candidate genes for schizophrenia; both are located on the short arm of chromosome 11. Multipoint linkage analyses excluded linkage of schizophrenia/schizoaffective disorder to both candidate genes in a sample of 15 multiplex and systematically recruited families. This result was not dependent on the definition of the affection status and on the specification of the mode of transmission (insofar as it is monogenic) of the disease. There was no evidence for a subgroup of families being linked. This result does not preclude the possibility that the D4 receptor gene or the TH gene has only a nonmajor effect on the genetic etiology of schizophrenia or that families in other populations are linked.
 ...
PMID:Absence of linkage between schizophrenia and the dopamine D4 receptor gene. 799 33

The discovery of a functional polymorphism within the dopamine D4 receptor gene (DRD4) has not only strengthened the hypotheses implicating DRD4 in the etiology of neuropyschiatric disorders, but also provided a genetic marker for testing these hypotheses. The possibility of the dopamine D4 receptor as a candidate gene for schizophrenia was investigated in a large Swedish kindred segregating for schizophrenia. Linkage to schizophrenia was tested by linkage analyses of 6 polymorphic markers (at 4 loci) in chromosome 11p15.5 including the dopamine D4 receptor (DRD4) and the tyrosine hydroxylase (TH) loci. Schizophrenia was excluded from close linkage to the DRD4 locus using two of the polymorphisms located within the dopamine D4 receptor gene. The first DRD4 polymorphism consists of variation in the number of a 48 bp imperfect direct repeat in the third exon; the second consists of a variable number of repeated G nucleotides in the first intron. In addition, some of the individuals homozygous for four or seven copies of 48 bp repeat alleles were tested for previously reported sequence variation among repeats. No single haplotype of the DRD4 alleles or haplotype of other markers in chromosome 11p15.5 was found to be common to the schizophrenic individuals in this family. Therefore, we find no evidence for linkage of the D4 receptor, or this region of 11p15.5, with genetic susceptibility to schizophrenia in this kindred.
 ...
PMID:Alleles at the dopamine D4 receptor locus do not contribute to the genetic susceptibility to schizophrenia in a large Swedish kindred. 813 5

Gilles de la Tourette Syndrome (TS) is neuropsychiatric disorder characterized by both motor and vocal tics affecting approximately 1/10,000 females and 1/2000 males. Because of the success of neuroleptics and other agents interacting with the dopaminergic system in the suppression of tics, a defect in the dopamine system has been hypothesized in the etiology of TS. In this paper we test the hypothesis that the dopamine D4 receptor (DRD4) is linked to the genetic susceptibility to TS in five families. We tested three polymorphisms in the DRD4 gene and a polymorphism in the closely linked locus, tyrosine hydroxylase (TH). We found no evidence for linkage of DRD4 or TH to TS using an autosomal dominant model with reduced penetrance or using non-parametric methods. The presence of a mutation that results in a truncated non-functional D4 receptor protein was also tested for, but was not observed in these families.
 ...
PMID:No evidence for a major gene effect of the dopamine D4 receptor gene in the susceptibility to Gilles de la Tourette syndrome in five Canadian families. 872 47

Associations of polymorphic genetic markers at the tyrosine hydroxylase (TH) and dopamine D4 receptor (DRD4) loci were examined in Scandinavian chronic alcoholics (n = 72) and control subjects (n = 67). Patients were divided into subgroups with regard to the presence of parental alcoholism and age of onset. Neither the TH nor the DRD4 allele distributions were significantly different when alcoholic samples were compared with control subjects. However, a tendency to high prevalence for 1 of the 5 TH alleles assayed (TH-K3) was observed in a subsample of 44 alcoholics characterized by late onset when compared with control subjects (27.3% vs. 10.6%, p = 0.041). Results suggest that no major influence on alcoholism is exerted through genes associated with the DRD4 or TH allelic markers examined.
 ...
PMID:Tyrosine hydroxylase and dopamine D4 receptor allelic distribution in Scandinavian chronic alcoholics. 904 70

We selected 83 patients with bipolar disorder type I or unipolar recurrent major depression and 71 healthy controls for genetic analysis of the tyrosine hydroxylase and the dopamine D4 receptor gene. No significant association was found between bipolar disorder type I and unipolar recurrent major depression and the polymorphisms located near these genes. Therefore, the hypothesis that the tyrosine hydroxylase and the dopamine D4 receptor genes may be involved in the etiology of bipolar disorder and unipolar recurrent major depression is not supported in our study.
 ...
PMID:Analysis of the tyrosine hydroxylase and dopamine D4 receptor genes in a Croatian sample of bipolar I and unipolar patients. 912 19

Human personality characteristics and vulnerability to psychopathology are to a large extent dependent upon genetic factors which have yet to be fully defined. The allele distribution of the dopamine D4 receptor (D4DR) and thrombocyte monoamine oxidase (trbc MAO) activity have both been associated with personality traits which are supposedly related, namely 'sensation seeking' according to Zuckerman and 'novelty seeking' according to Cloninger, respectively. In this report, the D4DR allele distribution and trbc MAO activity were studied in 31 psychiatric patients and 21 control subjects. Trbc MAO activity is a biochemical marker of personality that has been shown to be under strong genetic influence. However, no association between the D4DR alleles and trbc MAO could be observed in this material. To our knowledge, this is the first report comparing these two markers, and based upon the results obtained, we speculate that they may be connected with different types of overlapping personality characteristics. The allele distribution of the tyrosine hydroxylase (TH) gene was also determined. TH is the rate-limiting enzyme in the biosynthesis of catecholamines, and it is believed to be involved in different kinds of psychopathology. No covariation between TH gene alleles and trbc MAO activity or D4DR alleles was observed in this material.
 ...
PMID:Platelet monoamine oxidase activity in relation to alleles of dopamine D4 receptor and tyrosine hydroxylase genes. 935 Sep 59

To determine the role of genes in the chromosomal regions 11p15 and 4p12 in the development of alcohol dependence, a sample of alcoholics (n = 133) and normal controls (n = 89) were screened using polymorphisms in the dopamine D4 receptor (DRD4), tyrosine hydroxylase (TH), and GABA receptor beta1 (GABRbeta1) genes. Comparison of total alcoholics with normal controls for GABRbeta1 gene was highly significant (p = 0.004). The difference between type II alcoholics and normal controls for the same allele frequencies was also significant (p = 0.029). The allele distributions of the polymorphisms in the DRD4 and TH genes in alcoholics and normal controls were similar and their differences were not significant. Our association studies indicate that the GABRbeta1 gene may play a role in the development of alcoholism. Therefore, it is important to screen a sample of well-characterized alcoholics with functional polymorphisms in all of the GABAalpha receptor subunit genes and determine their relationship with alcoholism phenotypes. Results with TH and DRD4 genes indicate that these two genes may not play major roles in the development of alcoholism.
 ...
PMID:Human chromosomes 11p15 and 4p12 and alcohol dependence: possible association with the GABRB1 gene. 1049 Jul 12

Several studies have suggested a possible association of a polymorphism at the dopamine D4 receptor gene and attention-deficit hyperactivity disorder [LaHoste et al., 1996; Rowe et al., 1998; Smalley et al., 1998; Sunohara et al., submitted; Swanson et al., 1998]. The allele reported to be associated with attention-deficit hyperactivity disorder (ADHD) is the allele with seven copies of the 48 bp repeat in the third exon. We extend our study of the dopamine D4 gene and ADHD by testing for linkage using two additional polymorphisms in the dopamine D4 receptor gene and a polymorphism in the closely linked gene, tyrosine hydroxylase. We also searched for two previously reported deletions, a 13 bp and a 21 bp deletion in the first exon. We examined the haplotypes of three polymorphisms of the D4 receptor gene and observed biased transmission of two of these haplotypes. Our findings further support the role of the dopamine D4 gene in ADHD.
 ...
PMID:Further evidence from haplotype analysis for linkage of the dopamine D4 receptor gene and attention-deficit hyperactivity disorder. 1089 96


1 2 Next >>