{
  "abstract": "Background Epilepsy-related ligand–receptor complex, leucine-rich glioma-inactivated 1 ( LGI1)–a disintegrin and metalloproteinase 22 (ADAM22), regulates neuronal excitability and synaptic transmission and has emerged as a determinant of brain excitability. Epilepsy-related variants have been described in both LGI1 and ADAM 22 genes. A partial epilepsy, autosomal dominant lateral temporal epilepsy (ADLTE) is caused by an LGI1 heterozygous variant. A recessive developmental and epileptic encephalopathy with infantile onset is due to homozygous inactivating ADAM22 variants.Objective We present the case of Moroccan siblings with epileptic encephalopathy due to a homozygous variant within the LGI1 gene previously unreported in the homozygous state.Methods We performed whole-exome sequencing and family segregation analysis to identify and confirm the genetic cause of the condition in the affected siblings.Results The clinical features mimic ADAM22-related developmental and epileptic encephalopathy rather than the typical LGI1-associated autosomal dominant lateral temporal epilepsy. Family segregation analysis demonstrated variable expressivity, with asymptomatic carrier parents and a cousin with focal temporal epilepsy carrying the variant in the heterozygous state.Conclusion This case highlights a homozygous LGI1 variant previously unreported in the homozygous state, leading to a clinical presentation more reminiscent of ADAM22-related pathology rather than the classical ADLTE, expanding our understanding of LGI1-associated conditions.",
  "authors": [
    {
      "affiliations": [
        "Laboratory of Biomedical and Translational Research, Sidi Mohamed Ben Abdellah University Faculty of Medicine and Pharmacy, Fez, Morocco",
        "Engineering Science and Technology Doctoral Study Center, Faculty of Sciences and Technologies, Sidi Mohamed Ben Abdellah University, Fez, Morocco",
        "Unit of Medical Genetics and Oncogenetics, University Hospital Hassan II, Fez, Morocco"
      ],
      "name": "Hinde El Mouhi"
    },
    {
      "affiliations": [
        "Unit of Medical Genetics and Oncogenetics, University Hospital Hassan II, Fez, Morocco"
      ],
      "name": "Badreddine Elmakhzen"
    },
    {
      "affiliations": [
        "Unit of Medical Genetics and Oncogenetics, University Hospital Hassan II, Fez, Morocco"
      ],
      "name": "Amina Bouyahyaoui"
    },
    {
      "affiliations": [
        "Pediatrics, Sidi Mohamed Ben Abdellah University Faculty of Medicine and Pharmacy, Fez, Morocco"
      ],
      "name": "Mustapha Hida"
    },
    {
      "affiliations": [
        "Unit of Medical Genetics and Oncogenetics, University Hospital Hassan II, Fez, Morocco",
        "Medical Genetics, Sidi Mohamed Ben Abdellah University Faculty of Medicine and Pharmacy, Fez, Morocco"
      ],
      "name": "Karim Ouldim"
    },
    {
      "affiliations": [
        "Laboratory of Biomedical and Translational Research, Sidi Mohamed Ben Abdellah University Faculty of Medicine and Pharmacy, Fez, Morocco",
        "Unit of Medical Genetics and Oncogenetics, University Hospital Hassan II, Fez, Morocco"
      ],
      "name": "Laila Bouguenouch"
    },
    {
      "affiliations": [
        "Laboratory of Biomedical and Translational Research, Sidi Mohamed Ben Abdellah University Faculty of Medicine and Pharmacy, Fez, Morocco",
        "Pediatrics, Sidi Mohamed Ben Abdellah University Faculty of Medicine and Pharmacy, Fez, Morocco"
      ],
      "name": "Sana Chaouki"
    }
  ],
  "title": "Whole Exome Sequencing Identifies Novel Homozygous LGI1 Variant Mimicking ADAM22-Related Pathologies in a Moroccan Family",
  "uid": "cb6a78ed-743f-53fb-bedc-b123334d9e17"
}