No Mutation in the SLC2A3 Gene in Cohorts of GLUT1 Deficiency Syndrome-Like Patients Negative for SLC2A1 and in Patients with AHC Negative for ATP1A3.

The facilitative glucose transporter-1 (GLUT1) deficiency or de Vivo syndrome is a rare neuropediatric disorder characterized by drug-resistant epilepsy, acquired microcephaly, delayed psychomotor development, intermittent ataxia, and other paroxysmal neurological disorders due to the presence of dominant mutations in the SLC2A1 gene. Alternating hemiplegia of childhood (AHC) is another rare neuropediatric disorder characterized by episodes of hemiplegia developing during the first 1.5 years of life. Before the recent finding of the gene ATP1A3 as the major cause of AHC, a heterozygous missense mutation in the SLC2A1 gene encoding GLUT1 was described in one child with atypical AHC, suggesting some clinical overlap between AHC and GLUT1 deficiency syndrome (GLUT1DS1). Half of patients with symptoms evocative of GLUT1DS1 with hypoglycorrhachia and up to 25 % of patients with AHC remain molecularly undiagnosed. We investigated whether mutations in SLC2A3 encoding GLUT3, another glucose transporter predominant in the neuronal cell, may account the case of a cohort of 75 SLC2A1 negative GLUTDS1-like patients and seven patients with AHC who were negative for ATP1A3 and SLC2A1 mutations. Automated Sanger sequencing and qPCR analyses failed to detect any mutation of SLC2A3 in the patients analyzed, excluding this gene as frequently mutated in patients with GLUT1DS1 like or AHC.