Growth hormone deficiency: a possible complication of glucose transporter 1 deficiency?
Glucose transporter 1 deficiency syndrome (GLUT1DS) is an autosomal dominant disorder of brain energy metabolism caused by impaired GLUT1-mediated glucose transport across the blood-brain barrier. Although the clinical spectrum of this disorder is expanding rapidly, the growth patterns and endocrine status of these patients are not well known. We report the case of a boy aged 12 years and 7 months who has GLUT1DS complicated by growth failure. His failure to grow had progressed since birth, and his body height was 125 cm (-3.6 SDS). Growth hormone stimulation tests showed severe growth hormone deficiency (GHD), and we initiated GH replacement therapy. After 2 years of treatment, the boy's growth rate recovered from 1.7 cm/year before treatment, to 7.5 cm/year and 4.3 cm/year after treatment with no adverse effects. We speculate that GHD is a possible complication of GLUT1DS and discuss the underlying causative mechanism. GHD may be a possible complication of GLUT1DS.