A RARE GLUT 1 DEFICIENCY SYNDROME PRESENTING WITH SPEECH DELAY

Objectives: The glucose transporter type 1 (Glut1) is characterized by early infantile seizures, developmental delay, microcephaly and ataxia. Case: Two siblings were born at 38 gestational weeks, had no exceptions at birth, and have first-degree consanguinity between mother and father participated in the study. The first patient, a 3-year-old male, was referred with language delay, there was no seizure. On physical examination, he had mild mental retardation, an unsteady gait and he was able to use only single words such as a mom or dad. The other sibling presented with a similar language delay but later seizures accompanied. Complete blood count, routine biochemistry tests (creatinine, urea, AST/ALT, creatine kinase, TSH, f-T4, f-T3), basal metabolic tests (Tandem- Mass, urinary organic acid (UOA), serum amino acids) were all normal in both patients. The brain MRI and MR spectroscopy were normal. EEG showed generalized spike-multiple spike-wave activity. CSF/Blood glucose ratio was 35/140. As a result of mutation analyses, we found heterozygous c.1199G>A(p.R400H) pathogenic mutation in the SLC2A1 (NM_006516) gene. The ketogenic diet was started on both of the patients, and then, while one of the siblings' seizures stopped, the other siblings' speech developed and he started to make sentences. However, generalized discharges continued in the EEG (Figure 1). Conclusion: All patients presenting with speech delay should be evaluated by EEG. If the generalized epileptiform abnormality is accompanied, metabolic screening tests and brain MRI are normal, even if there is no seizure in the early period, GLUT1 deficiency syndrome should be kept in mind.
Keywords: glut1, speech delay, seizure