Symptoms, including fatigue, muscle weakness and digital vasospasm (Raynaud’s disease) prompted further investigation leading to identification of biallelic, SECISBP2 variants (c.668delT, c.IVS7-155,T>A; p.F223fs255X,p.fs295X+fs302X) causing selenoprotein deficiency and details of his case upto age 36 years have been reported previously8. The gene discussed is SECISBP2; the disease is hyperinsulinemic hypoglycemia, familial, 4.