Therefore, it is usually assumed that symptoms are merely functional in nature and prone to disappearance upon restoration of normal creatine levels (this assumption holds for the two creatine deficiency syndromes where creatine supplementation is effective, but in creatine transporter deficiency, such supplementation is useless because no creatine can reach the brain due to the transporter impairment [8]). The gene discussed is SLC6A8; the disease is hyperinsulinemic hypoglycemia, familial, 4.