Professor Jan Kraus passed away on the morning of July 4th after a battle with cancer. The research of Professor Kraus focused on propionic acidemia and classical homocystinuria. He dedicated his professional life to the understanding, diagnosis and treatment of classical homocystinuria and proprionic acidemia. Professor Kraus was recognised internationally as a brilliant scientist and considered by many as the “Father of Homocystinuria”. Professor Kraus’ career highlights include building a database of all the genetic mutations associated with homocystinuria, as well as discovering the enzyme replacement therapy known OT-58 (a pegylated version of the CBS enzyme) that is currently in human trials for classical homocystinuria. Professor Kraus served as a member of the HCU Networks Global Scientific Advisory Board. HCU Network Australia would like to take this opportunity to acknowledge his research contribution to the field and share our sincerest condolences to his wife, Eva, and family.