@article{CapetianRoessnerKorteetal.2021,
  author    = {Capetian, Philipp and Roessner, Veit and Korte, Caroline and Walitza, Susanne and Riederer, Franz and Taurines, Regina and Gerlach, Manfred and Moser, Andreas},
  title     = {Altered urinary tetrahydroisoquinoline derivatives in patients with Tourette syndrome: reflection of dopaminergic hyperactivity?},
  series = {Journal of Neural Transmission},
  volume    = {128},
  journal   = {Journal of Neural Transmission},
  issn      = {0300-9564},
  doi       = {10.1007/s00702-020-02289-6},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235771},
  pages     = {115-121},
  year      = {2021},
  abstract  = {Tetrahydroisoquinolines (TIQs) such as salsolinol (SAL), norsalsolinol (NSAL) and their methylated derivatives N-methyl-norsalsolinol (NMNSAL) and N-methyl-salsolinol (NMSAL), modulate dopaminergic neurotransmission and metabolism in the central nervous system. Dopaminergic neurotransmission is thought to play an important role in the pathophysiology of chronic tic disorders, such as Tourette syndrome (TS). Therefore, the urinary concentrations of these TIQ derivatives were measured in patients with TS and patients with comorbid attention-deficit/hyperactivity disorder (TS + ADHD) compared with controls. Seventeen patients with TS, 12 with TS and ADHD, and 19 age-matched healthy controls with no medication took part in this study. Free levels of NSAL, NMNSAL, SAL, and NMSAL in urine were measured by a two-phase chromatographic approach. Furthermore, individual TIQ concentrations in TS patients were used in receiver-operating characteristics (ROC) curve analysis to examine the diagnostic value. NSAL concentrations were elevated significantly in TS [434.67 ± 55.4 nmol/l (standard error of mean = S.E.M.), two-way ANOVA, p < 0.0001] and TS + ADHD patients [605.18 ± 170.21 nmol/l (S.E.M.), two-way ANOVA, p < 0.0001] compared with controls [107.02 ± 33.18 nmol/l (S.E.M.), two-way ANOVA, p < 0.0001] and NSAL levels in TS + ADHD patients were elevated significantly in comparison with TS patients (two-way ANOVA, p = 0.017). NSAL demonstrated an AUC of 0.93 ± 0.046 (S.E.M) the highest diagnostic value of all metabolites for the diagnosis of TS. Our results suggest a dopaminergic hyperactivity underlying the pathophysiology of TS and ADHD. In addition, NSAL concentrations in urine may be a potential diagnostic biomarker of TS.},
  language  = {en}
}
@article{FernandezCastilloCabanaDominguezKappeletal.2021,
  author    = {Fern{\`a}ndez-Castillo, No{\`e}lia and Cabana-Dom{\´i}nguez, Judit and Kappel, Djenifer B. and Torrico, B{\`a}rbara and Weber, Heike and Lesch, Klaus-Peter and Lao, Oscar and Reif, Andreas and Cormand, Bru},
  title     = {Exploring the contribution to ADHD of genes involved in Mendelian disorders presenting with hyperactivity and/or inattention},
  series = {Genes},
  volume    = {13},
  journal   = {Genes},
  number    = {1},
  issn      = {2073-4425},
  doi       = {10.3390/genes13010093},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-252346},
  year      = {2021},
  abstract  = {Attention-deficit hyperactivity disorder (ADHD) is a complex neurodevelopmental disorder characterized by hyperactivity, impulsivity, and/or inattention, which are symptoms also observed in many rare genetic disorders. We searched for genes involved in Mendelian disorders presenting with ADHD symptoms in the Online Mendelian Inheritance in Man (OMIM) database, to curate a list of new candidate risk genes for ADHD. We explored the enrichment of functions and pathways in this gene list, and tested whether rare or common variants in these genes are associated with ADHD or with its comorbidities. We identified 139 genes, causal for 137 rare disorders, mainly related to neurodevelopmental and brain function. Most of these Mendelian disorders also present with other psychiatric traits that are often comorbid with ADHD. Using whole exome sequencing (WES) data from 668 ADHD cases, we found rare variants associated with the dimension of the severity of inattention symptoms in three genes: KIF11, WAC, and CRBN. Then, we focused on common variants and identified six genes associated with ADHD (in 19,099 cases and 34,194 controls): MANBA, UQCC2, HIVEP2, FOPX1, KANSL1, and AUH. Furthermore, HIVEP2, FOXP1, and KANSL1 were nominally associated with autism spectrum disorder (ASD) (18,382 cases and 27,969 controls), as well as HIVEP2 with anxiety (7016 cases and 14,475 controls), and FOXP1 with aggression (18,988 individuals), which is in line with the symptomatology of the rare disorders they are responsible for. In conclusion, inspecting Mendelian disorders and the genes responsible for them constitutes a valuable approach for identifying new risk genes and the mechanisms of complex disorders.},
  language  = {en}
}
@phdthesis{Mortimer2021,
  author    = {Mortimer, Niall Patrick},
  title     = {ADHD Genetics in Mouse and Man},
  doi       = {10.25972/OPUS-23626},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236265},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder with an estimated heritability of around 70\%. In order to fully understand ADHD biology it is necessary to incorporate multiple different types of research. In this thesis, both human and animal model research is described as both lines of research are required to elucidate the aetiology of ADHD and development new treatments. The role of a single gene, Adhesion G protein-coupled receptor L3 (ADGRL3) was investigated using a knockout mouse model. ADGRL3 has putative roles in neuronal migration and synapse function. Various polymorphisms in ADGRL3 have been linked with an increased risk of attention deficit/hyperactivity disorder (ADHD) in human studies. Adgrl3-deficient mice were examined across multiple behavioural domains related to ADHD: locomotive activity, visuospatial and recognition memory, gait impulsivity, aggression, sociability and anxiety-like behaviour. The transcriptomic alterations caused by Adgrl3-depletion were analysed by RNA-sequencing of three ADHD-relevant brain regions: prefrontal cortex (PFC), hippocampus and striatum. Increased locomotive activity in Adgrl3-/- mice was observed across all tests with the specific gait analysis revealing subtle gait abnormalities. Spatial memory and learning domains were also impaired in these mice. Increased levels of impulsivity and sociability accompanying decreased aggression were also detected. None of these alterations were observed in Adgrl3+/- mice. The numbers of genes found to exhibit differential expression was relatively small in all brain regions sequenced. The absence of large scale gene expression dysregulation indicates a specific pathway of action, rather than a broad neurobiological perturbation. The PFC had the greatest number of differentially expressed genes and gene-set analysis of differential expression in this brain region detected a number of ADHD-relevant pathways including dopaminergic synapses as well as cocaine and amphetamine addiction. The most dysregulated gene in the PFC was Slc6a3 which codes for the dopamine transporter, a molecule vital to current pharmacological treatment of ADHD. The behavioural and transcriptomic results described in this thesis further validate Adgrl3 constitutive knockout mice as an experimental model of ADHD and provide neuroanatomical targets for future studies involving ADGRL3 modified animal models. The study of ADHD risk genes such as ADGRL3 requires the gene to be first identified using human studies. These studies may be genome based such as genome wide association studies (GWAS) or transcriptome based using microarray or RNA sequencing technology. To explore ADHD biology in humans the research described in this thesis includes both GWAS and trancriptomic data. A two-step transcriptome profiling was performed in peripheral blood mononuclear cells (PBMCs) of 143 ADHD subjects and 169 healthy controls. We combined GWAS and expression data in an expression-based Polygenic Risk Score (PRS) analysis in a total sample of 879 ADHD cases and 1919 controls from three different datasets. Through this exploratory study we found eight differentially expressed genes in ADHD and no support for the genetic background of the disorder playing a role in the aberrant expression levels identified. These results highlight promising candidate genes and gene pathways for ADHD and support the use of peripheral tissues to assess gene expression signatures for ADHD. This thesis illustrates how both human and animal model research is required to increase our understanding of ADHD. The animal models provide biological insight into the targets identified in human studies and may themselves provide further relevant gene targets. Only by combining research from disparate sources can we develop the thorough understanding on ADHD biology required for treatment development, which is the ultimate goal of translational science research.},
  language  = {en}
}
@article{ZieglerEhlisWeberetal.2021,
  author    = {Ziegler, Georg C. and Ehlis, Ann-Christine and Weber, Heike and Vitale, Maria Rosaria and Z{\"o}ller, Johanna E. M. and Ku, Hsing-Ping and Schiele, Miriam A. and K{\"u}rbitz, Laura I. and Romanos, Marcel and Pauli, Paul and Kalisch, Raffael and Zwanzger, Peter and Domschke, Katharina and Fallgatter, Andreas J. and Reif, Andreas and Lesch, Klaus-Peter},
  title     = {A Common CDH13 Variant is Associated with Low Agreeableness and Neural Responses to Working Memory Tasks in ADHD},
  series = {Genes},
  volume    = {12},
  journal   = {Genes},
  number    = {9},
  issn      = {2073-4425},
  doi       = {10.3390/genes12091356},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245220},
  year      = {2021},
  abstract  = {The cell—cell signaling gene CDH13 is associated with a wide spectrum of neuropsychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD), autism, and major depression. CDH13 regulates axonal outgrowth and synapse formation, substantiating its relevance for neurodevelopmental processes. Several studies support the influence of CDH13 on personality traits, behavior, and executive functions. However, evidence for functional effects of common gene variation in the CDH13 gene in humans is sparse. Therefore, we tested for association of a functional intronic CDH13 SNP rs2199430 with ADHD in a sample of 998 adult patients and 884 healthy controls. The Big Five personality traits were assessed by the NEO-PI-R questionnaire. Assuming that altered neural correlates of working memory and cognitive response inhibition show genotype-dependent alterations, task performance and electroencephalographic event-related potentials were measured by n-back and continuous performance (Go/NoGo) tasks. The rs2199430 genotype was not associated with adult ADHD on the categorical diagnosis level. However, rs2199430 was significantly associated with agreeableness, with minor G allele homozygotes scoring lower than A allele carriers. Whereas task performance was not affected by genotype, a significant heterosis effect limited to the ADHD group was identified for the n-back task. Heterozygotes (AG) exhibited significantly higher N200 amplitudes during both the 1-back and 2-back condition in the central electrode position Cz. Consequently, the common genetic variation of CDH13 is associated with personality traits and impacts neural processing during working memory tasks. Thus, CDH13 might contribute to symptomatic core dysfunctions of social and cognitive impairment in ADHD.},
  language  = {en}
}