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J Holik

Publications and source records attributed to J Holik.

34 records · Page 2Linked to original sources
PubMed1994

Analysis of GABAA receptor subunit genes in multiplex pedigrees with manic depression.

The gamma-aminobutyric acid (GABA) neurotransmitter system has been implicated in the pathogenesis of manic depression. Tests of this hypothesis can now be carried out due to the recent characterization of simple sequence repeat polymorphisms for the GABAA receptor alpha 1, alpha 2, alpha 4, alpha 5, alpha 6, beta 1, beta 3 and gamma 2 subunit genes. Using both parametric and non-parametric methods, we tested for linkage between manic depression and these polymorphisms in six multi-generational pedigrees. No evidence of linkage was found.

Adolescent↗
PubMed1994

Linkage analysis between schizophrenia and a microsatellite polymorphism for the D5 dopamine receptor gene.

Using 23 multiplex pedigrees we tested for linkage between schizophrenia and a microsatellite polymorphism for the D5 dopamine receptor gene (DRD5). Assuming autosomal dominant inheritance and a maximum penetrance of 0.6, an overall lod score of -4.54 was derived at 0% recombination. For recessive transmission the summary lod score was -8.37 at 0% recombination. These data suggest that mutations of the D5 dopamine receptor gene are unlikely to be of major etiological importance in the pathogeneses of schizophrenia in the families studied. However, our study does not exclude the D5 dopamine receptor gene as a candidate gene for schizophrenia because some of our families were not informative for linkage and because of the likelihood of genetic heterogeneity.

Adolescent↗
PubMed1993

Use of a neurophysiological trait in linkage analysis of schizophrenia.

Traditional diagnostic techniques may not provide all the information necessary to reveal the genetic causes of schizophrenia through linkage analysis. Use of neurophysiological indicator variables that are associated with the disease may increase the probability of detecting linkage. Such variables not only produce simpler phenotypes for analysis, but they also may be more proximal to the gene products involved in neurological dysfunctions underlying schizophrenia. We have used a previously characterized neurophysiological variable, the P50 evoked-auditory response, to search for chromosomal regions that may be of interest in the study of schizophrenia. Although our scan of over 300 markers did not show strong evidence for linkage to P50 in nine families, this exploratory analysis has revealed several chromosomal regions that may deserve further study.

Adolescent↗
PubMed1993

C to T nucleotide substitution in codon 713 of amyloid precursor protein gene not found in 86 unrelated schizophrenics from multiplex families.

Jones et al. Nature Genet 1:306-309, [1992] recently detected a C to T nucleotide transition (codon 713) in a highly conserved region of the beta-amyloid precursor gene in a single case of schizophrenia. Although the sequence variant may be a natural polymorphism, it is crucial to determine whether the mutation might be present in a small subset of schizophrenics. We isolated DNA from 86 unrelated chronic schizophrenics who had a first degree relative with chronic schizophrenia or chronic schizoaffective disorder. After PCR amplification of exon 17, we were unable to detect the presence of the codon 713 variant in these schizophrenic cases, as well as in 156 controls. Unless additional cases are found with the codon 713 mutation, it is unlikely that the sequence variant is pathogenic for schizophrenia.

Amyloid beta-Protein Precursor↗
PubMed1993

Linkage analysis of schizophrenia with five dopamine receptor genes in nine pedigrees.

Alterations in dopamine neurotransmission have been strongly implicated in the pathogenesis of schizophrenia for nearly 2 decades. Recently, the genes for five dopamine receptors have been cloned and characterized, and genetic and physical map information has become available. Using these five loci as candidate genes, we have tested for genetic linkage to schizophrenia in nine multigenerational families which include multiple affected individuals. In addition to testing conservative disease models, we have used a neurophysiological indicator variable, the P50 auditory evoked response. Deficits in gating of the P50 response have been shown to segregate with schizophrenia in this sample and may identify carriers of gene(s) predisposing for schizophrenia. Linkage results were consistently negative, indicating that a defect at any of the actual receptor sites is unlikely to be a major contributor to schizophrenia in the nine families studied.

Adolescent↗
PubMed1993

A genome-wide search for genes predisposing to manic-depression, assuming autosomal dominant inheritance.

Manic-depressive illness (MDI), also known as "bipolar affective disorder," is a common and devastating neuropsychiatric illness. Although pivotal biochemical alterations underlying the disease are unknown, results of family, twin, and adoption studies consistently implicate genetic transmission in the pathogenesis of MDI. In order to carry out linkage analysis, we ascertained eight moderately sized pedigrees containing multiple cases of the disease. For a four-allele marker mapping 5 cM from the disease gene, the pedigree sample has > 97% power to detect a dominant allele under genetic homogeneity and has > 73% power under 20% heterogeneity. To date, the eight pedigrees have been genotyped with 328 polymorphic DNA loci throughout the genome. When autosomal dominant inheritance was assumed, 273 DNA markers gave lod scores < -2.0 at recombination fraction (theta) = .0, 174 DNA loci produced lod scores < -2.0 at theta = .05, and 4 DNA marker loci yielded lod scores > 1 (chromosome 5--D5S39, D5S43, and D5S62; chromosome 11--D11S85). Of the markers giving lod scores > 1, only D5S62 continued to show evidence for linkage when the affected-pedigree-member method was used. The D5S62 locus maps to distal 5q, a region containing neurotransmitter-receptor genes for dopamine, norepinephrine, glutamate, and gamma-aminobutyric acid. Although additional work in this region may be warranted, our linkage results should be interpreted as preliminary data, as 68 unaffected individuals are not past the age of risk.

Adult↗
PubMed1992

Genetic linkage of the human gene for phenylethanolamine N-methyltransferase (PNMT), the adrenaline-synthesizing enzyme, to DNA markers on chromosome 17q21-q22.

We have determined the genetic location of the human gene encoding phenylethanolamine N-methyltransferase (PNMT), the terminal enzyme of the catecholamine pathway catalyzing the synthesis of epinephrine (adrenaline) from norepinephrine. This gene is linked to DNA markers on the long arm of chromosome 17, q21-q22, most closely to the DNA markers MFD15 (D17S250) (Zmax = 15.0, theta = 0.065) and fLB17.1 (Zmax = 14.6, theta = 0.045). Multipoint linkage analysis placed the PNMT locus in the interval fLB17.1-CMM86 (D17S74), at 4 centiMorgans (cM) distal to fLB17.1, and at 17 cM proximal to CMM86. Mapping of the PNMT gene will provide the basis for genetic linkage studies in families with disease which might pathogenetically involve this enzyme. The human chromosomal region 17q21-22 identified here to harbour the PNMT gene may be syntenic to the chromosomal region in the stroke-prone spontaneously hypertensive rat (SHR-SP) recently linked to blood-pressure regulation. As an increase of PNMT activity has been associated with the development of hypertension in SHR-SP, it will be of interest to perform comparative mapping of the PNMT gene.

Animals↗
PubMed1992

Tyrosine hydroxylase gene not linked to manic-depression in seven of eight pedigrees.

We ascertained 8 multigenerational pedigrees afflicted with multiple cases of bipolar and recurrent major depressive disorder. Alterations in dopaminergic and noradrenergic neurotransmission have been implicated in the pathogenesis of this disease, and tyrosine hydroxylase (TH) is the rate-limiting enzyme in the synthesis of these two catecholamines. As TH mutations could underlie susceptibility to manic-depression, we carried out a linkage analysis between this disease in 8 families and two RFLP probes that map to the TH gene region on the short arm of chromosome 11. Evidence of linkage was not found in 7 of 8 kindreds.

Bipolar Disorder↗
PubMed1992

Linkage analysis of the D1 dopamine receptor gene and manic depression in six families.

Disturbances in dopaminergic activity may play an important role in the pathogenesis of manic depression. The effects of dopamine are mediated by at least five G protein coupled receptors, D1, D2, D3, D4 and D5. Recently, three separate research groups have cloned and characterized the D1 dopamine receptor, which localizes to 5q35.1. We undertook a linkage analysis between the D1 receptor polymorphisms and manic depression in six families in which segregation of the disease was consistent with autosomal dominant inheritance. A highly polymorphic flanking DNA marker, CRI-L1200, was also analyzed as the D1 gene RFLPs were relatively uninformative in our families. Multipoint analyses of manic depression and these DNA markers resulted in lod scores of less than -3.0 at the D1 locus, indicating that the D1 dopamine receptor gene does not confer an inherited susceptibility to manic-depressive illness in the families studied.

Bipolar Disorder↗
PubMed1976

Attempt at "immunological castration" as an approach to the problem of the involvement of testosterone in control of expression of certain mouse antigens.

Adult male mice of the strain B10.A were immunized with a testosterone-protein conjugate, testosterone 3-(O-CARBOXYMETHYL)-oxime-bovine serum albumin which contained 27-75 steroid residues/mol BSA. Two different immunization doses of the conjugate were used, respectively, 2 x 40 mug and 2 x 200 mug in complete Freund's adjuvant or in alum adjuvant. There were two groups of control males, non-immunized and immunized with BSA in adjuvant. In the pooled immune sera, antibodies to testosterone were determined by radioimmunoassay; their titre ranged between 7 and 10. On histological sections of testes, inhibition of spermatogenesis (manifested by a sower frequency or even absence of tubules producing mature sperm, reduced frequency of tubular cells and their degenerative changes) was observed in almost all males immunized with the higher dose of the conjugate. In such animals, increased frequency of interstitial cells (except vascular elements) and enlarged nuclei of Leydig cells were found. In spite of these signs of a hyperproduction of testosterone by the Leydig cells, the product seemed to have lacked its normal biological activity as suggested not only by the low activity of spermatogenesis, but also by a significantly subnormal level of the androgen-dependent serum protein Ss.

Animals↗
PubMedDate not supplied

Linkage analysis of schizophrenia: the D1 dopamine receptor gene and several flanking DNA markers.

Alterations in dopaminergic activity may play an important role in the pathogenesis of schizophrenia. The central effects of dopamine are mediated by at least five G protein-coupled receptors, D1, D2, D3, D4 and D5. The D1 receptor maps to 5q35.1 and it identifies an Eco RI as well as a Taq I RFLP. In the present study we undertook a linkage analysis between the D1 receptor RFLPs and schizophrenia in 9 multigenerational families in which segregation of disease was consistent with autosomal dominant inheritance and reduced penetrance. Several flanking DNA markers were also analyzed as the D1 receptor RFLPs were relatively uninformative in our families. Pairwise analyses of schizophrenia and several flanking markers indicate that inheritability of this region is unlikely to be involved in the pathogenesis of schizophrenia in the 9 families studied.

Chromosome Mapping↗
PubMedDate not supplied

Human dopamine transporter gene not linked to schizophrenia in multigenerational pedigrees.

A large body of data suggests that perturbations in brain dopaminergic transmission play a role in the pathogenesis of schizophrenia. Recently, the gene for the human dopamine transporter has been cloned and polymorphisms have been identified. Because mutations of the dopamine transporter gene might underlie the cause of schizophrenia in a subset of families, we undertook a linkage analysis between schizophrenia in 9 families and a dopamine transporter gene polymorphism. Evidence of linkage was not found in most families assuming autosomal dominant or recessive inheritance.

Carrier Proteins↗
PubMedDate not supplied

Manic-depression and the norepinephrine transporter gene.

Six multigenerational pedigrees containing multiple cases of manic-depression were genotyped with a DNA polymorphism for the norepinephrine transporter (NET) gene. Using both parametric and nonparametric methods, no evidence of linkage between manic-depression and the NET gene was found.

Adolescent↗