Affiliation:
1. Division of Neurology, Department of Pediatrics, Montreal Children's Hospital McGill University Health Centre Montreal Quebec Canada
2. Division of Neurology, Department of Pediatrics British Columbia Children's Hospital Vancouver British Columbia Canada
3. Research Institute of the McGill University Health Centre Montreal Quebec Canada
4. Department of Neurology and Neurosurgery, Montreal Children's Hospital McGill University Health Centre Montreal Quebec Canada
Abstract
AbstractLegius syndrome is a rare genetic disorder, caused by heterozygous SPRED1 pathogenic variants, which shares phenotypic features with neurofibromatosis type 1 (NF1). Both conditions typically involve café‐au‐lait macules, axillary freckling, and macrocephaly; however, patients with NF1 are also at risk for tumors, such as optic nerve gliomas and neurofibromas. Seizure risk is known to be elevated in NF1, but there has been little study of this aspect of Legius syndrome. The reported epilepsy incidence is 3.3%–5%, well above the general population incidence of ~0.5%–1%, but the few reports in the literature have very little data regarding epilepsy phenotype. We identified two unrelated individuals, both with Legius syndrome and epilepsy, and performed thorough phenotyping. One individual's mother also had Legius syndrome and now‐resolved childhood epilepsy, as well as reports of more distant relatives who also had multiple café‐au‐lait macules and seizures. Both probands had experienced childhood‐onset focal seizures, with normal brain MRI. In one patient, EEG later showed apparently generalized epileptiform abnormalities. Based on the data from this small case series and literature review, seizure risk is increased in people with Legius syndrome, but the epilepsy prognosis appears to be generally good, with patients having either self‐limited or pharmacoresponsive courses.