ABSTRACT
CONTEXT: Genetic, neuroimaging, and molecular neurobiological evidence support the hypothesis that the disconnectivity syndrome in schizophrenia (SZ) could arise from failures of saltatory conduction and abnormalities at the nodes of Ranvier (NOR) interface where myelin and axons interact. OBJECTIVE: To identify abnormalities in the expression of oligodendroglial genes and proteins that participate in the formation, maintenance, and integrity of the NOR in SZ. DESIGN: The messenger RNA (mRNA) expression levels of multiple NOR genes were quantified in 2 independent postmortem brain cohorts of individuals with SZ, and generalizability to protein expression was confirmed. The effect of the ANK3 genotype on the mRNA expression level was tested in postmortem human brain. Case-control analysis tested the association of the ANK3 genotype with SZ. The ANK3 genotype's influence on cognitive task performance and functional magnetic resonance imaging activation was tested in 2 independent cohorts of healthy individuals. SETTING: Research hospital. Patients Postmortem samples from patients with SZ and healthy controls were used for the brain expression study (n = 46) and the case-control analysis (n = 272). Healthy white men and women participated in the cognitive (n = 513) and neuroimaging (n = 52) studies. MAIN OUTCOME MEASURES: The mRNA and protein levels in postmortem brain samples, genetic association with schizophrenia, cognitive performance, and blood oxygenation level-dependent functional magnetic resonance imaging. RESULTS: The mRNA expression of multiple NOR genes was decreased in schizophrenia. The ANK3 rs9804190 C allele was associated with lower ANK3 mRNA expression levels, higher risk for SZ in the case-control cohort, and poorer working memory and executive function performance and increased prefrontal activation during a working memory task in healthy individuals. CONCLUSIONS: These results point to abnormalities in the expression of genes and protein associated with the integrity of the NOR and suggest them as substrates for the disconnectivity syndrome in SZ. The association of ANK3 with lower brain mRNA expression levels implicates a molecular mechanism for its genetic, clinical, and cognitive associations with SZ.
Subject(s)
Ankyrins/biosynthesis , Ranvier's Nodes/genetics , Schizophrenia/genetics , Alleles , Animals , Ankyrins/antagonists & inhibitors , Ankyrins/genetics , Case-Control Studies , Cohort Studies , Executive Function , Female , Genotype , Haloperidol/administration & dosage , Humans , Male , Memory, Short-Term , Polymorphism, Genetic , Ranvier's Nodes/pathology , Rats , Rats, Sprague-Dawley , Schizophrenia/pathologyABSTRACT
The Autism Genome Project (AGP) Consortium recently reported genome-wide significant association between autism and an intronic single nucleotide polymorphism marker, rs4141463, within the MACROD2 gene. In the present study we attempted to replicate this finding using an independent case-control design of 1,170 cases with autism spectrum disorder (ASD) (874 of which fulfilled narrow criteria for Autism (A)) from five centers within Europe (UK, Germany, the Netherlands, Italy, and Iceland), and 35,307 controls. The combined sample size gave us a non-centrality parameter (NCP) of 11.9, with 93% power to detect allelic association of rs4141463 at an alpha of 0.05 with odds ratio of 0.84 (the best odds ratio estimate of the AGP Consortium data), and for the narrow diagnosis of autism, an NCP of 8.9 and power of 85%. Our case-control data were analyzed for association, stratified by each center, and the summary statistics were combined using the meta-analysis program, GWAMA. This resulted in an odds ratio (OR) of 1.03 (95% CI 0.944-1.133), with a P-value of 0.5 for ASD and OR of 0.99 (95% CI 0.88-1.11) with P-value = 0.85 for the Autism (A) sub-group. Therefore, this study does not provide support for the reported association between rs4141463 and autism.
Subject(s)
Autistic Disorder/genetics , Genome-Wide Association Study , Polymorphism, Single Nucleotide , Case-Control Studies , Europe , Genetic Predisposition to Disease , Genotype , HumansSubject(s)
Abnormalities, Multiple/pathology , Ear/abnormalities , Growth Disorders/pathology , Intellectual Disability/pathology , Tetralogy of Fallot/pathology , Abnormalities, Multiple/genetics , Child, Preschool , Humans , Karyotyping , Male , Syndactyly/pathology , Syndrome , Toes/abnormalitiesABSTRACT
We report two siblings with congenital generalized hypertrichosis and distinctive facial appearance consistent with the dysmorphic facial features described in Ambras syndrome. The patients were born to non-consanguineous, phenotypically normal parents. This is the first report of affected siblings and could be explained by either autosomal recessive inheritance or by germline mosaicism for an autosomal dominant gene. We compared the phenotype of our patients to descriptions of reported cases and discuss phenotypic variability.
