Academy of Medical Sciences of I.R. Iran Archives of Iranian Medicine 1029-2977 25 12 2022 12 01 Characterizing Genotypes and Phenotypes Associated with Dysfunction of Channel-Encoding Genes in a Cohort of Patients with Intellectual Disability 788 797 10.34172/aim.2022.124 EN Naeim Ehtesham https://orcid.org/0000-0002-1769-6329 Meysam Mosallaei Maryam Beheshtian https://orcid.org/0000-0002-5609-7724 Shahrouz Khoshbakht Mahsa Fadaee Raheleh Vazehan Mehrshid Faraji Zonooz Parvaneh Karimzadeh https://orcid.org/0000-0002-6302-9973 Kimia Kahrizi Hossein Najmabadi https://orcid.org/0000-0002-6084-7778 Journal Article 10.34172/aim.2022.124 2021 10 03 2021 12 20 Background: Ion channel dysfunction in the brain can lead to impairment of neuronal membranes and generate several neurological diseases, especially neurodevelopmental disorders. Methods: In this study, we set out to delineate the genotype and phenotype spectrums of 14 Iranian patients from 7 families with intellectual disability (ID) and/or developmental delay (DD) in whom genetic mutations were identified by next-generation sequencing (NGS) in 7 channel-encoding genes: KCNJ10, KCNQ3, KCNK6, CACNA1C, CACNA1G, SCN8A, and GRIN2B. Moreover, the data of 340 previously fully reported ID and/or DD cases with a mutation in any of these seven genes were combined with our patients to clarify the genotype and phenotype spectrum in this group. Results: In total, the most common phenotypes in 354 cases with ID/DD in whom mutation in any of these 7 channel-encoding genes was identified were as follows: ID (77.4%), seizure (69.8%), DD (59.8%), behavioral abnormality (29.9%), hypotonia (21.7%), speech disorder (21.5%), gait disturbance (20.9%), and ataxia (20.3%). Electroencephalography abnormality (33.9%) was the major brain imaging abnormality. Conclusion: The results of this study broaden the molecular spectrum of channel pathogenic variants associated with different clinical presentations in individuals with ID and/or DD.