ESPE Abstracts

Background: GLUT1 deficiency syndrome (GLUT1DS) is a treatable epileptic encephalopathy resulting from impaired glucose transport into the brain. Clinical features comprise motor and mental developmental delay, seizures with infantile onset, deceleration of head growth often resulting in acquired microcephaly, and a movement disorder with ataxia, dystonia, and spasticity. While it is known that ketogenic diet may cause growth retardation, GH deficiency (GHD) may represent another possible cause of growth failure in children with GLUT1DS.

Case presentation: We report a case of GHD in a 10-year-old Caucasian boy with GLUT1DS. The child was admitted for evaluation of growth failure. His target height was 181 cm (+1 S.D.s). He had mild facial dysmorphism (epicanthus, telecanthus, hypertelorism), his height was 123.8 cm (−2.56 S.D.s), his growth velocity was 2.1 cm/year in the previous year (−4.33 S.D.s). Two GH provocative tests (with arginine and clonidine) showed GH deficiency (GH peak: 9.4 ng/ml on the first test, 7.4 ng/ml on the second test), with IGF1 in the lower range (106 ng/mL, normal range: 88–452). The patient was started on GH replacement therapy at a dose of 26 μg/kg per day, with marked improvement of his growth velocity after just 3 months of therapy. After 6 months of therapy his height was 128.5 cm (−2.42 S.D.s) with a growth velocity of 19.2 cm/year (+0.96 S.D.s). The diagnosis of GHD was established before the diagnosis of GLUT1DS, excluding the confounding role of ketogenic diet.

Conclusion: We speculate that GHD may represent a poorly recognised clinical feature of GLUT1DS and that under-diagnosis could derive from the fact that growth failure may be ascribed to ketogenic diet and therefore not further investigated.