Editors' note: SYNGAP1 encephalopathy: A distinctive generalized developmental and epileptic encephalopathy

Abstract

In “ SYNGAP1 encephalopathy: A distinctive generalized developmental and epileptic encephalopathy,” Vlaskamp et al. reviewed the phenotype of 57 patients with SYNGAP1 mutations/microdeletions and found that this disorder is characterized by generalized epilepsy (often eyelid myoclonia with absences) particularly after eating, developmental delay, moderate to severe intellectual disability, behavioral impairment, sleeping problems, hypotonia, and gait abnormalities. Wolf et al. emphasized that in their experience, chewing and biting were the characteristic triggers for seizures during eating. They also noted these patients to be sensitive to eyelid closure. Vlaskamp et al. replied that eyelid closure sensitivity was very common in their cohort. They proposed that the limited photosensitivity observed may be attributed to EEG timing (because photosensitivity is age dependent), technical difficulties, or behavioral problems interfering with the assessment. Vlaskamp et al. found that 18% of patients with SYNGAP1 encephalopathy became seizure-free after age 7, most of whom were on valproate or lamotrigine. Fung described a patient with SYNGAP1 mutation who had improved seizure frequency and development on a ketogenic diet, but this was complicated by pneumonia due to lipid aspiration. Vlaskamp et al. responded that they had seen one patient with SYNGAP1 encephalopathy improve markedly on the ketogenic diet and that although less than 10% of patients on the diet develop lipoid pneumonia, Fung's case serves as an important reminder of the potential for aspiration in patients with developmental and epileptic encephalopathies. In “ SYNGAP1 encephalopathy: A distinctive generalized developmental and epileptic encephalopathy,” Vlaskamp et al. reviewed the phenotype of 57 patients with SYNGAP1 mutations/microdeletions and found that this disorder is characterized by generalized epilepsy (often eyelid myoclonia with absences) particularly after eating, developmental delay, moderate to severe intellectual disability, behavioral impairment, sleeping problems, hypotonia, and gait abnormalities. Wolf et al. emphasized that in their experience, chewing and biting were the characteristic triggers for seizures during eating. They also noted these patients to be sensitive to eyelid closure. Vlaskamp et al. replied that eyelid closure sensitivity was very common in their cohort. They proposed that the limited photosensitivity observed may be attributed to EEG timing (because photosensitivity is age dependent), technical difficulties, or behavioral problems interfering with the assessment. Vlaskamp et al. found that 18% of patients with SYNGAP1 encephalopathy became seizure-free after age 7, most of whom were on valproate or lamotrigine. Fung described a patient with SYNGAP1 mutation who had improved seizure frequency and development on a ketogenic diet, but this was complicated by pneumonia due to lipid aspiration. Vlaskamp et al. responded that they had seen one patient with SYNGAP1 encephalopathy improve markedly on the ketogenic diet and that although less than 10% of patients on the diet develop lipoid pneumonia, Fung's case serves as an important reminder of the potential for aspiration in patients with developmental and epileptic encephalopathies.