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Walker CP, Pessoa ALS, Figueiredo T, Rafferty M, Melo US, Nóbrega PR, Murphy N, Kok F, Zatz M, Santos S, Cho RY. Loss-of-function mutation in inositol monophosphatase 1 (IMPA1) results in abnormal synchrony in resting-state EEG. Orphanet J Rare Dis 2019; 14:3. [PMID: 30616629 PMCID: PMC6322245 DOI: 10.1186/s13023-018-0977-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 12/11/2018] [Indexed: 12/14/2022] Open
Abstract
Background Dysregulation of the inositol cycle is implicated in a wide variety of human diseases, including developmental defects and neurological diseases. A homozygous frameshift mutation in IMPA1, coding for the enzyme inositol monophosphatase 1 (IMPase), has recently been associated with severe intellectual disability (ID) in a geographically isolated consanguineous family in Northeastern Brazil (Figueredo et al., 2016). However, the neurophysiologic mechanisms that mediate the IMPA1 mutation and associated ID phenotype have not been characterized. To this end, resting EEG (eyes-open and eyes-closed) was collected from the Figueredo et al. pedigree. Quantitative EEG measures, including mean power, dominant frequency and dominant frequency variability, were investigated for allelic associations using multivariate family-based association test using generalized estimating equations. Results We found that the IMPA1 mutation was associated with relative decreases in frontal theta band power as well as altered alpha-band variability with no regional specificity during the eyes-open condition. For the eyes-closed condition, there was altered dominant theta frequency variability in the central and parietal regions. Conclusions These findings represent the first human in vivo phenotypic assessment of brain function disturbances associated with a loss-of-function IMPA1 mutation, and thus an important first step towards an understanding the pathophysiologic mechanisms of intellectual disability associated with the mutation that affects this critical metabolic pathway.
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Affiliation(s)
- Christopher P Walker
- Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX, USA.
| | - Andre L S Pessoa
- Hospital Infantil Albert Sabin, Fortaleza, Brazil.,Universidade Estadual do Ceará-UECE, Fortaleza, Brazil
| | - Thalita Figueiredo
- Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Instituto de Biociências, Universidade de São Paulo (USP), São Paulo, SP, 05508-090, Brazil
| | - Megan Rafferty
- Department of Psychiatry, Baylor College of Medicine, Houston, TX, USA
| | - Uirá S Melo
- Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Instituto de Biociências, Universidade de São Paulo (USP), São Paulo, SP, 05508-090, Brazil
| | | | - Nicholas Murphy
- Department of Psychiatry, Baylor College of Medicine, Houston, TX, USA
| | - Fernando Kok
- Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Instituto de Biociências, Universidade de São Paulo (USP), São Paulo, SP, 05508-090, Brazil
| | - Mayana Zatz
- Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Instituto de Biociências, Universidade de São Paulo (USP), São Paulo, SP, 05508-090, Brazil
| | - Silvana Santos
- Department of Biology, State University of Paraíba (UEPB), Campina Grande, PB, Brazil
| | - Raymond Y Cho
- Department of Psychiatry, Baylor College of Medicine, Houston, TX, USA
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