Professor Theo J. Visser, Rotterdam, The Netherlands, has passed away aged 68 years.
Theo Visser was born in Rotterdam, The Netherlands. After graduating from secondary school, he obtained his MSc in Organic Chemistry at the Technical University of Delft in 1972. He then moved to the group of Professor Georg Hennemann at the Erasmus Medical Centre in Rotterdam. He started as a research associate but soon became an independent scientist. In 1980, Theo defended his PhD thesis, entitled Thyroid Hormone Deiodination.
In his early career, he was involved in the development of different radioimmunoassays for iodothyronines that proved to be instrumental for scientific and clinical purposes.
In 1981, he moved to the laboratory of Professor Reed Larsen in Boston, USA, as a visiting scientist, together with his wife Rian and their young daughters Ellen and Renske. He regularly shared many pleasant memories both from his scientific and family life in that period, which always put a smile on his face. Soon after his return to the Netherlands, he was appointed as professor of endocrinology at the Erasmus Medical Centre at the age of 37 years.
In the 1980s, Theo made seminal discoveries on the identification and mechanisms of deiodination. His research in thyroid hormone transport culminated in 2003 in the discovery of MCT8, the most specific thyroid hormone transporter known to date. Soon afterwards, Theo was the first to identify patients with defective MCT8. The tremendous impact in the field, but also for the lives of families caring for an MCT8-deficient child, is difficult to overestimate. In recent years, he was also among the first to identify patients with thyroid hormone resistance caused by a mutation of the TRα1 receptor. His current research involved the identification of novel thyroid hormone transporters and the identification of new clinical syndromes due to defects in thyroid hormone signaling genes.
Theo was very committed to various (inter)national scientific organizations. He was member of the Executive Committee (1984–1989) and President (2011–2013) of the ETA and served many committees of endocrine and thyroid associations. Theo’s huge contributions were recognized by many awards from professional socie ties. Markers of his esteem include the Harrington-De Visscher Prize (ETA, 1991), Pitt Rivers Lecture (British Thyroid Foundation, 2005), Edwin B. Astwood Award (Endocrine Society, 2009), Merck-Serono Prize (ETA, 2009), John B. Stanbury Thyroid Pathophysiology Medal (ATA, 2013), European Medal (Society for Endocrinology, 2014), ETJ lecture (ETA, 2016), and Lissitzky Award (ETA, 2017).
Theo inspired many generations of scientists during his outstanding career of over 4 decades. Not only in open-minded supportive discussions, but also through setting an example by his dedicated, hard, and energetic work, he was a kind, inspiring, and beloved mentor to many researchers. In addition, Theo was well known for his pure interest in all people, regardless of whether they were respected professors or newly starting junior researchers. His charming personality and humor were known to everyone, and many have enjoyed his active engaging in social events and parties.
Our sincere sympathies are with his wife Rian, his two daughters, and his grandchildren who will miss a beloved man, father, and granddad.
We have lost a colleague, mentor, brilliant scientist, and a great person and friend.
We will miss him deeply.
Roel Docter
Georg Hennemann
Eric P. Krenning
Robin P. Peeters
W. Edward Visser
