The relationship between genotype and phenotype in Chinese children with glucose transporter type 1 deficiency syndrome.

Background: Glucose transporter type 1 deficiency syndrome (Glut1DS) is a treatable neurogenetic metabolic disorder caused by pathogenic variants in the Methods: Clinical data of Glut1DS patients, including age of onset, clinical manifestations, cerebrospinal fluid (CSF) analysis, and Results: A total of 93 patients with Glut1DS were included, among whom 65 (70%) were classical phenotypes (including 55 early-onset classical cases and 10 late-onset classical cases), and 28 (30%) were non-classical phenotypes. Significant differences were observed among early-onset classical, late-onset classical, and non-classical groups in terms of age of onset ( Conclusion: Glut1DS predominantly manifests as the classical phenotype, with the early-onset classical phenotype presenting at the youngest age and exhibiting the most severe clinical symptoms. Patients with this type also showed lower CSF glucose levels and a lower CSF glucose to blood glucose ratio compared to other types. Missense and in-frame indel variants were associated with a later age of onset compared to other types of genetic variants. No significant correlations were found between genotype and clinical classification or CSF glucose levels.