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Rovelli V, Longo N. Phenylketonuria and the brain. Mol Genet Metab 2023; 139:107583. [PMID: 37105048 DOI: 10.1016/j.ymgme.2023.107583] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 04/14/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023]
Abstract
Classic phenylketonuria (PKU) is caused by defective activity of phenylalanine hydroxylase (PAH), the enzyme that coverts phenylalanine (Phe) to tyrosine. Toxic accumulation of phenylalanine and its metabolites, left untreated, affects brain development and function depending on the timing of exposure to elevated levels. The specific mechanisms of Phe-induced brain damage are not completely understood, but they correlate to phenylalanine levels and on the stage of brain growth. During fetal life, high levels of phenylalanine such as those seen in maternal PKU can result in microcephaly, neuronal loss and corpus callosum hypoplasia. Elevated phenylalanine levels during the first few years of life can cause acquired microcephaly, severe cognitive impairment and epilepsy, likely due to the impairment of synaptogenesis. During late childhood, elevated phenylalanine can cause alterations in neurological functioning, leading to ADHD, speech delay and mild IQ reduction. In adolescents and adults, executive function and mood are affected, with some of the abnormalities reversed by better control of phenylalanine levels. Altered brain myelination can be present at this stage. In this article, we review the current knowledge about the consequences of high phenylalanine levels in PKU patients and animal models through different stages of brain development and its effect on cognitive, behavioural and neuropsychological function.
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Affiliation(s)
- Valentina Rovelli
- Clinical Department of Pediatrics, University of Milan, ASST Santi Paolo e Carlo, San Paolo Hospital, Milan, Italy.
| | - Nicola Longo
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
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2
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Ashe K, Kelso W, Farrand S, Panetta J, Fazio T, De Jong G, Walterfang M. Psychiatric and Cognitive Aspects of Phenylketonuria: The Limitations of Diet and Promise of New Treatments. Front Psychiatry 2019; 10:561. [PMID: 31551819 PMCID: PMC6748028 DOI: 10.3389/fpsyt.2019.00561] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 07/17/2019] [Indexed: 12/30/2022] Open
Abstract
Phenylketonuria (PKU) is a recessive disorder of phenylalanine metabolism due to mutations in the gene for phenylalanine hydroxylase (PAH). Reduced PAH activity results in significant hyperphenylalaninemia, which leads to alterations in cerebral myelin and protein synthesis, as well as reduced levels of serotonin, dopamine, and noradrenaline in the brain. When untreated, brain development is grossly disrupted and significant intellectual impairment and behavioral disturbance occur. The advent of neonatal heel prick screening has allowed for diagnosis at birth, and the institution of a phenylalanine restricted diet. Dietary treatment, particularly when maintained across neurodevelopment and well into adulthood, has resulted in markedly improved outcomes at a cognitive and psychiatric level for individuals with PKU. However, few individuals can maintain full dietary control lifelong, and even with good control, an elevated risk remains of-in particular-mood, anxiety, and attentional disorders across the lifespan. Increasingly, dietary recommendations focus on maintaining continuous dietary treatment lifelong to optimize psychiatric and cognitive outcomes, although the effect of long-term protein restricted diets on brain function remains unknown. While psychiatric illness is very common in adult PKU populations, very little data exist to guide clinicians on optimal treatment. The advent of new treatments that do not require restrictive dietary management, such as the enzyme therapy Pegvaliase, holds the promise of allowing patients a relatively normal diet alongside optimized mental health and cognitive functioning.
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Affiliation(s)
- Killian Ashe
- Neuropsychiatry Unit, Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Wendy Kelso
- Neuropsychiatry Unit, Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Sarah Farrand
- Neuropsychiatry Unit, Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Julie Panetta
- Statewide Adult Metabolic Service, Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Tim Fazio
- Statewide Adult Metabolic Service, Royal Melbourne Hospital, Melbourne, VIC, Australia.,Melbourne Medical School, University of Melbourne, Melbourne, VIC, Australia
| | - Gerard De Jong
- Statewide Adult Metabolic Service, Royal Melbourne Hospital, Melbourne, VIC, Australia.,Melbourne Medical School, University of Melbourne, Melbourne, VIC, Australia
| | - Mark Walterfang
- Neuropsychiatry Unit, Royal Melbourne Hospital, Melbourne, VIC, Australia.,Melbourne Neuropsychiatry Centre, University of Melbourne and North-Western Mental Health, Melbourne, VIC, Australia.,Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
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Teraishi T, Kajiwara M, Hori H, Sasayama D, Hidese S, Matsuo J, Ishida I, Kajiwara Y, Ozeki Y, Ota M, Hattori K, Higuchi T, Kunugi H. 13C-phenylalanine breath test and serum biopterin in schizophrenia, bipolar disorder and major depressive disorder. J Psychiatr Res 2018; 99:142-150. [PMID: 29454221 DOI: 10.1016/j.jpsychires.2018.01.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 12/23/2017] [Accepted: 01/26/2018] [Indexed: 10/18/2022]
Abstract
Phenylalanine is required for the synthesis of the neurotransmitters dopamine, noradrenaline, and adrenaline. The rate-limiting step for phenylalanine metabolism is catalyzed by phenylalanine hydroxylase (PAH) and its cofactor tetrahydrobiopterin. We aimed to detect altered phenylalanine metabolism in major psychiatric disorders using the l-[1-13C]phenylalanine breath test (13C-PBT) and serum biopterin levels. We also investigated association of PAH mutations with schizophrenia and phenylalanine metabolism. 13C-phenylalanine (100 mg) was orally administered, and the breath 13CO2/12CO2 ratio was monitored for 120 min in four groups: 103 patients with schizophrenia (DSM-IV), 39 with bipolar disorder, 116 with major depressive disorder (MDD), and 241 healthy controls. Serum biopterin levels were measured by high performance liquid chromatography. Mutation screening of PAH exons was performed by direct sequencing in 46 schizophrenia patients. Association analysis was performed using six tag single nucleotide polymorphisms and the PAH Arg53His mutation by TaqMan assays in 616 schizophrenia patients and 1194 healthy controls. Analyses of covariance controlling for age, sex, and body weight showed that the index for the amount of exhaled 13CO2 was significantly lower in the schizophrenia group than in the other three groups (all p < 0.05). Biopterin levels in schizophrenia and MDD were significantly lower than those in controls. Biopterin levels correlated with 13C-PBT indices in controls. PAH polymorphisms were not associated with schizophrenia or 13C-PBT indices. 13C-PBT revealed reduced phenylalanine metabolism in schizophrenia, though we obtained no evidence of involvement of PAH polymorphism. Serum biopterin levels were lower in schizophrenia and MDD, warranting further investigation.
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Affiliation(s)
- Toshiya Teraishi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawahigashi, Kodaira, Tokyo, 187-8502, Japan
| | - Masahiro Kajiwara
- Yokohama University of Pharmacy, 601 Matano-cho, Totsuka-ku, Yokohama, Kanagawa, 245-0066, Japan; Tri-X Biomedical, Inc., 4-12-5-406, Minamiyawata, Ichikawa, Chiba, 272-0023, Japan
| | - Hiroaki Hori
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawahigashi, Kodaira, Tokyo, 187-8502, Japan
| | - Daimei Sasayama
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawahigashi, Kodaira, Tokyo, 187-8502, Japan
| | - Shinsuke Hidese
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawahigashi, Kodaira, Tokyo, 187-8502, Japan
| | - Junko Matsuo
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawahigashi, Kodaira, Tokyo, 187-8502, Japan
| | - Ikki Ishida
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawahigashi, Kodaira, Tokyo, 187-8502, Japan
| | - Yasuhiro Kajiwara
- Yokohama University of Pharmacy, 601 Matano-cho, Totsuka-ku, Yokohama, Kanagawa, 245-0066, Japan
| | - Yuji Ozeki
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawahigashi, Kodaira, Tokyo, 187-8502, Japan; Department of Psychiatry, Dokkyo Medical University School of Medicine, Tochigi, 321-0293, Japan
| | - Miho Ota
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawahigashi, Kodaira, Tokyo, 187-8502, Japan
| | - Kotaro Hattori
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawahigashi, Kodaira, Tokyo, 187-8502, Japan
| | - Teruhiko Higuchi
- National Center of Neurology and Psychiatry, 4-1-1, Ogawahigashi, Kodaira, Tokyo, 187-8551, Japan
| | - Hiroshi Kunugi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawahigashi, Kodaira, Tokyo, 187-8502, Japan.
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Mathai AJ, Kanwar J, Okusaga O, Fuchs D, Lowry CA, Peng X, Giegling I, Hartmann AM, Konte B, Friedl M, Gragnoli C, Reeves GM, Groer MW, Rosenthal RN, Rujescu D, Postolache TT. Blood Levels of Monoamine Precursors and Smoking in Patients with Schizophrenia. Front Public Health 2016; 4:182. [PMID: 27626030 PMCID: PMC5003942 DOI: 10.3389/fpubh.2016.00182] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 08/15/2016] [Indexed: 01/08/2023] Open
Abstract
Smoking is highly prevalent in patients with schizophrenia and exerts a negative impact on cardiovascular mortality in these patients. Smoking has complex interactions with monoamine metabolism through the ability of cigarette smoke to suppress Type 1 T helper cell (Th1) type immunity, the immunophenotype that is implicated in phenylalanine hydroxylase (PAH) dysfunction and tryptophan (Trp) breakdown to kynurenine (Kyn) via indoleamine 2,3-dioxygenase. Nicotine also induces tyrosine hydroxylase (TH) gene expression, leading to increased synthesis of catecholamines. Furthermore, there is evidence for PAH dysfunction in schizophrenia. This study aimed to compare the plasma levels of selected monoamine precursors and their metabolites in smokers vs. non-smokers in a large sample of patients with schizophrenia. We measured plasma phenylalanine (Phe), tyrosine (Tyr), Trp, and Kyn levels using high-performance liquid chromatography and calculated Phe:Tyr and Kyn:Trp ratios in 920 patients with schizophrenia. Analysis of variance and linear regression analyses were used to compare these endpoints between three groups of patients with schizophrenia: (1) current smokers, (2) past smokers, and (3) non-smokers. There were significant differences among the three groups with regards to Tyr levels [F(2,789) = 3.77, p = 0.02], with current smokers having lower Tyr levels when compared with non-smokers (p = 0.02). Kyn levels and Kyn:Trp ratio were different among the three groups [F(2,738) = 3.17, p = 0.04, F(2,738) = 3.61, p = 0.03] with current smokers having lower Kyn levels (p = 0.04) and higher Kyn:Trp ratio (p = 0.02) when compared with past smokers. These findings need to be replicated with protocols that include healthy controls to further elucidate the neurobiological underpinnings of altered Tyr and Kyn levels in smokers. Results do suggest potential molecular links between schizophrenia and smoking that may represent biomarkers and treatment targets for reducing an important modifiable cause of general morbidity and mortality in patients with schizophrenia.
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Affiliation(s)
- Ashwin Jacob Mathai
- Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, MD, USA; Saint Elizabeths Hospital Psychiatry Residency Training Program, Washington, DC, USA
| | - Jyoti Kanwar
- Mood and Anxiety Program, University of Maryland School of Medicine , Baltimore, MD , USA
| | - Olaoluwa Okusaga
- Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Dietmar Fuchs
- Division of Biological Chemistry, Biocenter Innsbruck Medical University , Innsbruck , Austria
| | - Christopher A Lowry
- Department of Integrative Physiology, Center for Neuroscience, University of Colorado Boulder , Boulder, CO , USA
| | - Xiaoqing Peng
- Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, MD, USA; Saint Elizabeths Hospital Psychiatry Residency Training Program, Washington, DC, USA
| | - Ina Giegling
- Department of Psychiatry, Martin-Luther-University of Halle-Wittenberg , Halle , Germany
| | - Annette M Hartmann
- Department of Psychiatry, Martin-Luther-University of Halle-Wittenberg , Halle , Germany
| | - Bettina Konte
- Department of Psychiatry, Martin-Luther-University of Halle-Wittenberg , Halle , Germany
| | - Marion Friedl
- Department of Psychiatry, Martin-Luther-University of Halle-Wittenberg , Halle , Germany
| | - Claudia Gragnoli
- Public Health Sciences, Penn State College of Medicine, Hershey, PA, USA; Public Health Sciences, Penn State College of Medicine, Hershey, PA, USA
| | - Gloria M Reeves
- Division of Child and Adolescent Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA; University of Maryland Child and Adolescent Mental Health Innovations Center, Baltimore, MD, USA
| | | | - Richard N Rosenthal
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai , New York, NY , USA
| | - Dan Rujescu
- Department of Psychiatry, Martin-Luther-University of Halle-Wittenberg , Halle , Germany
| | - Teodor T Postolache
- Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, MD, USA; VISN 5 Capitol Health Care Network Mental Illness Research Education and Clinical Center (MIRECC), Baltimore, MD, USA; Rocky Mountain MIRECC, Denver, CO, USA
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Vieland VJ, Walters KA, Lehner T, Azaro M, Tobin K, Huang Y, Brzustowicz LM. Revisiting schizophrenia linkage data in the NIMH Repository: reanalysis of regularized data across multiple studies. Am J Psychiatry 2014; 171:350-9. [PMID: 24170318 PMCID: PMC4041610 DOI: 10.1176/appi.ajp.2013.11121766] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
OBJECTIVE The Combined Analysis of Psychiatric Studies (CAPS) project conducted extensive review and regularization across studies of all schizophrenia linkage data available as of 2011 from the National Institute of Mental Health-funded Center for Collaborative Genomic Studies on Mental Disorders, also known as the Human Genetics Initiative (HGI). The authors reanalyzed the data using statistical methods tailored to accumulation of evidence across multiple, potentially highly heterogeneous, sets of data. METHOD Data were subdivided based on contributing study, major population group, and presence or absence within families of schizophrenia with a substantial affective component. The posterior probability of linkage (PPL) statistical framework was used to sequentially update linkage evidence across these data subsets (omnibus results). RESULTS While some loci previously implicated using the HGI data were also identified in the present omnibus analysis (2q36.1, 15q23), others were not. Several loci were found that had not previously been reported in the HGI samples but are supported by independent linkage or association studies (3q28, 12q23.1, 11p11.2, Xq26.1). Not surprisingly, differences were seen across population groups. Of particular interest are signals on 11p15.3, 11p11.2, and Xq26.1, for which data from families with a substantial affective component support linkage while data from the remaining families provide evidence against linkage. All three of these loci overlap with loci reported in independent studies of bipolar disorder or mixed bipolar-schizophrenia samples. CONCLUSIONS Public data repositories provide the opportunity to leverage large multisite data sets for studying complex disorders. Analysis with a statistical method specifically designed for such data enables us to extract new information from an existing data resource.
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Benjamin S, Lauterbach MD, Stanislawski AL. Congenital and acquired disorders presenting as psychosis in children and young adults. Child Adolesc Psychiatr Clin N Am 2013; 22:581-608. [PMID: 24012075 DOI: 10.1016/j.chc.2013.04.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A review of the published literature found 60 congenital and acquired disorders with symptoms that include psychosis in youth. The prevalence, workup, genetics, and associated neuropsychiatric features of each disorder are described. Eighteen disorders (30%) have distinct phenotypes (doorway diagnoses); 18 disorders (30%) are associated with intellectual disability; and 43 disorders (72%) have prominent neurologic signs. Thirty-one disorders (52%) can present without such distinct characteristics, and are thus more easily overlooked. A systematic and cost-effective differential diagnostic approach based on estimated prevalence and most prominent associated signs is recommended.
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Affiliation(s)
- Sheldon Benjamin
- Departments of Psychiatry and Neurology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA.
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Gao XX, Cui J, Zheng XY, Li ZY, Choi YH, Zhou YZ, Tian JS, Xing J, Tan XJ, Du GH, Qin XM. An investigation of the antidepressant action of xiaoyaosan in rats using ultra performance liquid chromatography-mass spectrometry combined with metabonomics. Phytother Res 2012; 27:1074-85. [PMID: 22975930 DOI: 10.1002/ptr.4805] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Revised: 07/10/2012] [Accepted: 07/16/2012] [Indexed: 11/09/2022]
Abstract
A rapid, highly sensitive, and selective method was applied in a non-invasive way to investigate the antidepressant action of Xiaoyaosan (XYS) using ultra performance liquid chromatography-mass spectrometry (UPLC-MS) and chemometrics. Many significantly altered metabolites were used to explain the mechanism. Venlafaxine HCl and fluoxetine HCl were used as chemical positive control drugs with a relatively clear mechanism of action to evaluate the efficiency and to predict the mechanism of action of XYS. Urine obtained from rats subjected to chronic unpredictable mild stress (CUMS) was analyzed by UPLC-MS. Distinct changes in the pattern of metabolites in the rat urine after CUMS production and drug intervention were observed using partial least squares-discriminant analysis. The results of behavioral tests and multivariate analysis showed that CUMS was successfully reproduced, and a moderate-dose XYS produced significant therapeutic effects in the rodent model, equivalent to those of the positive control drugs, venlafaxine HCl and fluoxetine HCl. Metabolites with significant changes induced by CUMS were identified, and 17 biomarker candidates for stress and drug intervention were identified. The therapeutic effect of XYS on depression may involve regulation of the dysfunctions of energy metabolism, amino acid metabolism, and gut microflora changes. Metabonomic methods are valuable tools for measuring efficacy and mechanisms of action in the study of traditional Chinese medicines.
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Affiliation(s)
- Xiao-Xia Gao
- Modern Research Center for Traditional Chinese Medicine of Shanxi University, No.92, Wucheng Road, Taiyuan 030006, PR China
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Abstract
Phenylalanine is an essential amino acid required for the synthesis of catecholamines including dopamine. Altered levels of phenylalanine and its metabolites in blood and cerebrospinal fluid have been reported in schizophrenia patients. This study attempted to examine for the first time whether phenylalanine kinetics is altered in schizophrenia using L-[1-(13)C]phenylalanine breath test ((13)C-PBT). The subjects were 20 chronically medicated schizophrenia patients (DSM-IV) and the same number of age- and sex-matched controls. (13)C-phenylalanine (99 atom% (13)C; 100 mg) was administered orally and the breath (13)CO(2) /(12)CO(2) ratio was monitored for 120 min. The possible effect of antipsychotic medication (risperidone (RPD) or haloperidol (HPD) treatment for 21 days) on (13)C-PBT was examined in rats. Body weight (BW), age and diagnostic status were significant predictors of the area under the curve of the time course of Δ(13)CO(2) (‰) and the cumulative recovery rate (CRR) at 120 min. A repeated measures analysis of covariance controlled for age and BW revealed that the patterns of CRR change over time differed between the patients and controls and that Δ(13)CO(2) was lower in the patients than in the controls at all sampling time points during the 120 min test, with an overall significant difference between the two groups. Chronic administration of RPD or HPD had no significant effect on (13)C-PBT indices in rats. Our results suggest that (13)C-PBT is a novel laboratory test that can detect altered phenylalanine kinetics in chronic schizophrenia patients. Animal experiments suggest that the observed changes are unlikely to be attributable to antipsychotic medication.
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Talkowski ME, McClain L, Allen T, Bradford LD, Calkins M, Edwards N, Georgieva L, Go R, Gur R, Gur R, Kirov G, Chowdari K, Kwentus J, Lyons P, Mansour H, McEvoy J, O’ Donovan MC, O’Jile J, Owen MJ, Santos A, Savage R, Toncheva D, Vockley G, Wood J, Devlin B, Nimgaonkar VL. Convergent patterns of association between phenylalanine hydroxylase variants and schizophrenia in four independent samples. Am J Med Genet B Neuropsychiatr Genet 2009; 150B:560-9. [PMID: 18937293 PMCID: PMC2738981 DOI: 10.1002/ajmg.b.30862] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recessive mutations in the phenylalanine hydroxylase (PAH) gene predispose to phenylketonuria (PKU) in conjunction with dietary exposure to phenylalanine. Previous studies have suggested PAH variations could confer risk for schizophrenia, but comprehensive follow-up has not been reported. We analyzed 15 common PAH "tag" SNPs and three exonic variations that are rare in Caucasians but common in African-Americans among four independent samples (total n = 5,414). The samples included two US Caucasian cohorts (260 trios, 230 independent cases, 474 controls), Bulgarian families (659 trios), and an African-American sample (464 families, 401 controls). Analyses of both US Caucasian samples revealed associations with five SNPs; most notably the common allele (G) of rs1522305 from case-control analyses (z = 2.99, P = 0.006). This SNP was independently replicated in the Bulgarian cohort (z = 2.39, P = 0.015). A non-significant trend was also observed among African-American families (z = 1.39, P = 0.165), and combined analyses of all four samples were significant (rs1522305: chi(2) = 23.28, 8 d.f., P = 0.003). Results for rs1522305 met our a priori criteria for statistical significance, namely an association that was robust to multiple testing correction in one sample, a replicated risk allele in multiple samples, and combined analyses that were nominally significant. Case-control results in African-Americans detected an association with L321L (P = 0.047, OR = 1.46). Our analyses suggest several associations at PAH, with consistent evidence for rs1522305. Further analyses, including additional variations and environmental influences such as phenylalanine exposure are warranted.
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Affiliation(s)
- Michael E. Talkowski
- Department of Psychiatry, University of Pittsburgh, Sofia, Bulgaria
,Department of Human Genetics, University of Pittsburgh, Sofia, Bulgaria
| | - Lora McClain
- Department of Psychiatry, University of Pittsburgh, Sofia, Bulgaria
| | - Trina Allen
- Department of John Umstead Hospital, Duke University Medical Center, Sofia, Bulgaria
| | | | - Monica Calkins
- Department of Psychiatry, University of Pennsylvania, Sofia, Bulgaria
| | - Neil Edwards
- Department of Psychiatry, University of Tennessee, Sofia, Bulgaria
| | - Lyudmila Georgieva
- Department of Psychological Medicine, Cardiff University School of Medicine, Sofia, Bulgaria
| | - Rodney Go
- Department of Psychiatry, Behavioral Neurobiology, and Epidemiology, University of Alabama Birmingham, Sofia, Bulgaria
| | - Ruben Gur
- Department of Psychiatry, University of Pennsylvania, Sofia, Bulgaria
| | - Raquel Gur
- Department of Psychiatry, University of Pennsylvania, Sofia, Bulgaria
| | - George Kirov
- Department of Psychological Medicine, Cardiff University School of Medicine, Sofia, Bulgaria
| | | | - Joseph Kwentus
- Department of Psychiatry and Human Behavior, University of Mississippi, Sofia, Bulgaria
| | - Paul Lyons
- Department of Neurology, University of Virginia, Sofia, Bulgaria
| | - Hader Mansour
- Department of Psychiatry, University of Pittsburgh, Sofia, Bulgaria
| | - Joseph McEvoy
- Department of John Umstead Hospital, Duke University Medical Center, Sofia, Bulgaria
| | - Michael C. O’ Donovan
- Department of Psychological Medicine, Cardiff University School of Medicine, Sofia, Bulgaria
| | - Judith O’Jile
- Department of Psychiatry and Human Behavior, University of Mississippi, Sofia, Bulgaria
| | - Michael J. Owen
- Department of Psychological Medicine, Cardiff University School of Medicine, Sofia, Bulgaria
| | - Alberto Santos
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Sofia, Bulgaria
| | - Robert Savage
- Department of Psychiatry, Behavioral Neurobiology, and Epidemiology, University of Alabama Birmingham, Sofia, Bulgaria
| | - Draga Toncheva
- Department of Medical Genetics, Medical University, Sofia, Bulgaria
| | - Gerard Vockley
- Department of Pediatrics, University of Pittsburgh, Sofia, Bulgaria
| | - Joel Wood
- Department of Psychiatry, University of Pittsburgh, Sofia, Bulgaria
| | - Bernie Devlin
- Department of Psychiatry, University of Pittsburgh, Sofia, Bulgaria
,Department of Human Genetics, University of Pittsburgh, Sofia, Bulgaria
| | - Vishwajit L. Nimgaonkar
- Department of Psychiatry, University of Pittsburgh, Sofia, Bulgaria
,Department of Human Genetics, University of Pittsburgh, Sofia, Bulgaria
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Bergen SE, Fanous AH, Walsh D, O’Neill FA, Kendler KS. Polymorphisms in SLC6A4, PAH, GABRB3, and MAOB and modification of psychotic disorder features. Schizophr Res 2009; 109:94-7. [PMID: 19268543 PMCID: PMC2682723 DOI: 10.1016/j.schres.2009.02.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2008] [Revised: 02/09/2009] [Accepted: 02/10/2009] [Indexed: 12/01/2022]
Abstract
We tested four genes [phenylalanine hydroxylase (PAH), the serotonin transporter (SLC6A4), monoamine oxidase B (MAOB), and the gamma-aminobutyric acid A receptor beta-3 subunit (GABRB3)] for their impact on five schizophrenia symptom factors: delusions, hallucinations, mania, depression, and negative symptoms. In a 90 family subset of the Irish Study of High Density Schizophrenia Families, the PAH 232 bp microsatellite allele demonstrated significant association with the delusions factor using both QTDT (F=8.0, p=.031) and QPDTPHASE (chi-square=12.54, p=.028). Also, a significant association between the GABRB3 191 bp allele and the hallucinations factor was detected using QPDTPHASE (chi-square=15.51, p=.030), but not QTDT (chi-square=2.07, p=.560).
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Affiliation(s)
- Sarah E. Bergen
- Virginia Commonwealth University, Department of Human and Molecular Genetics, Richmond, Virginia, USA,Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Ayman H. Fanous
- Virginia Commonwealth University, Department of Psychiatry, Richmond, Virginia, USA,Washington VA Medical Center, Washington, DC, USA,Georgetown University Medical Center, Department of Psychiatry, Washington, DC, USA,Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Dermot Walsh
- Health Research Board and St. Loman’s Hospital, Dublin, Ireland
| | | | - Kenneth S. Kendler
- Virginia Commonwealth University, Department of Human and Molecular Genetics, Richmond, Virginia, USA,Virginia Commonwealth University, Department of Psychiatry, Richmond, Virginia, USA,Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, Virginia, USA
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11
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Sand PG. Comments on the paper by D. Li and L. He: Meta-analysis shows association between the tryptophan hydroxylase (TPH) gene and schizophrenia. Hum Genet 2007; 122:409-11. [PMID: 17653577 DOI: 10.1007/s00439-007-0383-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Devlin B, Klei L, Myles-Worsley M, Tiobech J, Otto C, Byerley W, Roeder K. Genetic liability to schizophrenia in Oceanic Palau: a search in the affected and maternal generation. Hum Genet 2007; 121:675-84. [PMID: 17436020 DOI: 10.1007/s00439-007-0358-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Accepted: 03/20/2007] [Indexed: 12/22/2022]
Abstract
While liability to schizophrenia (Scz) is due to genetic and environmental factors, specific factors are largely unknown. We postulate a two-hit model for Scz, in which initial liability is generated during fetal brain development: this "hit" is precipitated by environmental stressors biologically interacting with maternal genetic vulnerability to the stress. Additional liability to Scz is generated by individual genetic vulnerability. To evaluate these putative levels of vulnerability, we search in the genome of both affected individuals and their mothers for variation that differs, statistically, from that in the general population. For parental analyses, mothers were treated as "affected," rather than their offspring, and the fathers were treated as "controls". We used a sample from the Palauan population: 175 individuals diagnosed with Scz, broadly defined; 87 mothers and 45 fathers of affected individuals. Pedigree and diagnostic data were available on 2,953 living and deceased subjects. DNA from 553 individuals was genotyped for short tandem repeats (STR) spaced approximately every 10 cM across the genome. We tested for association between affection status and STR alleles; such an approach was reasonable, despite the widely spaced markers, because this population has far-ranging linkage disequilibrium (LD). Results for the truly affected individuals were modest, whereas results from the maternal generation were promising. For a recessive model and a test for excess allele matching across mothers, significant findings occurred for D20S481, D10S1221, D6S1021, D13S317, and D18S976. Regions in which at least two adjacent markers produced substantial association statistics include 2p12-11.2, 2q24.1-32.1, 6q12-14.1, 10q23.2-24.21, 12q23.2-24.21 and 17q23.2-23.3.
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Affiliation(s)
- Bernie Devlin
- Department of Psychiatry, University of Pittsburgh School of Medicine, 3811 O'Hara Street, Pittsburgh, PA 15213, USA.
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Li D, He L. Meta-analysis shows association between the tryptophan hydroxylase (TPH) gene and schizophrenia. Hum Genet 2006; 120:22-30. [PMID: 16741719 DOI: 10.1007/s00439-006-0190-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Accepted: 04/13/2006] [Indexed: 10/24/2022]
Abstract
A number of studies have suggested an association between schizophrenia and the tryptophan hydroxylase (TPH) and tyrosine hydroxylase (TH) genes. On the other hand, several studies attempting to replicate these findings have produced mixed results, possibly reflecting inadequate statistical power of the individual studies as well as the heterogeneity inherent in schizophrenia. In an attempt to clarify this inconsistency our meta-analysis has combined all the studies using multiple research methods published up to February 2006 to give a comprehensive picture of the role of three hydroxylase-related genes. The TPH A218C/A779C (OR = 1.18, 95% C.I. 1.06-1.33, P = 0.004) revealed a significant association with schizophrenia. However, the evidence for the TH and phenylalanine hydroxylase (PAH) genes was weak. No publication bias was detected in current studies. The findings, which may implicate the involvement of TPH in the pathogenesis of schizophrenia, have potentially important clinical, scientific and public health implications as well as providing a putative basis for the study of hydroxylase-related drugs. To our knowledge, this is the first meta-analysis of association between the three genes and schizophrenia.
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Affiliation(s)
- Dawei Li
- Bio-X Center, Shanghai Jiao Tong University, Hao Ran Building, 1954 Hua Shan Road, Shanghai 200030, People's Republic of China
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Richardson MA, Chao HM, Read LL, Clelland JD, Suckow RF. Investigation of the phenylalanine hydroxylase gene and tardive dyskinesia. Am J Med Genet B Neuropsychiatr Genet 2006; 141B:195-7. [PMID: 16402341 DOI: 10.1002/ajmg.b.30281] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Phenylketonuria (PKU), an inborn error of phenylalanine metabolism, has been shown to be a risk factor for tardive dyskinesia (TD). In male psychiatric patients there was a significant relationship between TD and measures of plasma phenylalanine following ingestion of a standardized phenylalanine dose that was indicative of higher brain availability of phenylalanine in patients with TD. In addition, a medical food formulation consisting of branched chain amino acids, which compete with phenylalanine for transport across the blood-brain barrier, has been demonstrated to be an efficacious treatment for TD. Cumulatively these findings suggested that TD was related to phenylalanine metabolism and thus that sequence variants in the gene for phenylalanine hydroxylase (PAH), the rate-limiting enzyme in the catabolism of phenylalanine, could be associated with TD susceptibility. Genetic screening of PAH in a group of 123 psychiatric patients revealed ten sequence polymorphisms and two mutations, but none appeared to be a significant risk factor for TD.
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Affiliation(s)
- Mary Ann Richardson
- Movement Disorders and Molecular Psychiatry Division, Nathan Kline Institute for Psychiatric Research, New York State Office of Mental Health, Orangeburg, New York 10962, USA
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Richardson MA, Read LL, Taylor Clelland CL, Reilly MA, Chao HM, Guynn RW, Suckow RF, Clelland JD. Evidence for a tetrahydrobiopterin deficit in schizophrenia. Neuropsychobiology 2005; 52:190-201. [PMID: 16244500 DOI: 10.1159/000089002] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Tetrahydrobiopterin (BH(4)) is a vital cofactor maintaining availability of the amine neurotransmitters [dopamine (DA), noradrenaline (NA), and serotonin (5-HT)], regulating the synthesis of nitric oxide (NO) by nitric oxide synthase (NOS), and stimulating and modulating the glutamatergic system (directly and indirectly). These BH(4) properties and their potential relevance to schizophrenia led us to investigate the hypothesis of a study group (healthy controls, n=37; schizophrenics, n=154) effect on fasting plasma total biopterin levels (a measure of BH(4)). Study analysis showed a highly significant deficit of total biopterins for the schizophrenic sample after partialling out the effects of potential confounds of gender, age, ethnicity, neuroleptic use history and dose of current use, 24-hour dietary phenylalanine/protein ratio (a dietary variable relevant to BH(4) synthesis), and plasma phenylalanine (which stimulates BH(4) synthesis). A mean decrement of 34% in plasma total biopterins for schizophrenics from control values supports clinical relevance for the finding. In a subsample (21 controls and 23 schizophrenics), sequence analysis was done of the GTP cyclohydrolase I feedback regulatory gene and no mutations were found in the coding region of the gene. A deficiency of BH(4) could lead to hypofunction of the systems of DA, NA, 5-HT, NOS/NO, and glutamate, all of which have been independently implicated in schizophrenia psychopathology. Further, evidence has been accumulating which implicates the critical interdependence of these neurotransmitter systems in schizophrenia; this concept, along with the present study finding of a biopterin deficit, suggests that further study of the BH(4) system in schizophrenia is warranted and desirable.
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Affiliation(s)
- M A Richardson
- The Nathan S. Kline Institute for Psychiatric Research, New York State Office of Mental Health, Orangeburg, NY 10962, USA
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