public static void children(long concept)
        {
            string guid = "GUID"; //Enter your GUID here.
                int relationship = 116680003; //The SNOMED relationship for "IS A". See SNOMED documentation for more details.
                using (SnApiServiceClient client = new SnApiServiceClient())
                {

                        foreach (var item in client.GetNeighbours(concept, "0", relationship, guid))
                        {

                            if (item.PorCHorS == "C") //Don't recount parent concepts, only grab children.
                            {
                            Console.WriteLine(item.NeighbourConceptId.ToString() + "," + item.NeighbourFSN);
                            children(item.NeighbourConceptId); //Recall children recursively
                            }
                        }

                }
        }
        public static void children(long concept)
        {
            
                string guid = "GUID"; //Enter your GUID here.
                int relationship = 116680003; //The SNOMED relationship for "IS A". See SNOMED documentation for more details.
                using (SnApiServiceClient client = new SnApiServiceClient())
                {
                    
                        foreach (var item in client.GetNeighbours(concept, "0", relationship, guid))
                        {

                            if (item.PorCHorS == "C") //Don't recount parent concepts, only grab children.
                            {
                            Console.WriteLine(item.NeighbourConceptId.ToString() + "," + item.NeighbourFSN);
                            children(item.NeighbourConceptId); //Recall children recursively
                            }
                        }
                    
                    
                }
            }