Jean Dussault

Recipient of the Robert Guthrie Award 1998

In Memoriam : Jean-H Dussault (1941-2003)
Jean Dussault died on March 23, 2003, in his 62nd year of life, thus ending a remarkable career filled with outstanding scientific achievements.

Jean Dussault’s personal and scientific accomplishments earned him wide respect and affection. His earliest scientific contribution in late 1972, was the development of a new blood test for congenital hypothyroidism. He continued with many pioneering and important contributions over the past three decades including a neonatal screening program for congenital hypothyroidism and his research on clinical disorders of the thyroid and also on the mode of action of thyroid hormones in the developing brain.

Jean Dussault was born and grew up in Quebec city, Canada. He received his bachelor’s degree from the University of Montreal in 1960 and his M.D. in 1965 from the University of Laval. He undertook his internship followed by a 2 yr residency in Medicine at the Enfant-Jesus Hospital in Quebec city. His formal research training began in 1967 as a research fellow in Endocrinology under the mentorship of Dr. R. Volpe at Wellesley hospital (University of Toronto, Canada) and then in the department of Pediatrics and Medicine, UCLA, Harbor General Hospital (Torrance, California) under the mentorship of Drs D.A. Fisher and D.H. Salomon. In 1971, he came back to Quebec city and was promoted to Assistant professor at Laval University School of Medicine in the department of Endocrinology and Metabolism. In 1981, he became professor of Medicine at Laval University school of Medicine (service of Endocrinology and Metabolism). He worked at the CHU Laval where he was an active scientist for 32 yrs. In 1974, he was made director of the Screening Program for Congenital hypothyroidism; the Quebec Network for Genetic Disease. In parallel, he established an independent laboratory and resumed his research on thyroid hormone action in the developing brain. Between 1986 and 1996, he was made Chief of the Unit of Molecular Medicine Genetics at the CHUL Research Center.

Jean Dussault’s contributions to Endocrinology are monumental. With well over 200 publications, he and his colleagues made pioneering contributions in areas ranging from basic mechanisms of thyroid hormone action in the developing brain, to the diagnosis and treatment of thyroid dysfunction. Jean’s efforts led to the development of a new neonatal diagnosis test for congenital hypothyroidism, a test presently used worldwide. In 2000, about 150 million newborns have been tested for congenital hypothyroidism using this test.

In parallel, he focused his basic research on the study of the mechanisms of action of thyroid hormones in the developing brain. In the mid-70s, Jean demonstrated the absence of placental transfer of maternal thyroxin and reported the biochemical consequences of neonatal thyroid hormone deficiency in the developing brain. Thereafter, Jean studied the expression and the regional distribution of thyroid hormone receptors in the developing brain by Scatchard’s analysis. At that time, no antibodies against thyroid receptors were available because of purification difficulties . In 1988, he purified the thyroid receptor proteins by using affinity chromatography and produced the first monoclonal antibody against the thyroid hormone receptor. This antibody has been extensively used by him and by other groups to study the cellular localization of thyroid receptors not only in the developing brain but also in several peripheral tissues. In 1986, Dr Jack Puymirat joined Dussault’s team to further extend the analysis of the effects of thyroid hormones in the developing brain. Using primary neuronal cultures grown in a chemically defined medium, he and Dr. Puymirat demonstrated that thyroid hormones act directly on neuronal cells and that their major effects are on neurite outgrowth. In mid 2001, Jean reduced his research activities because of the disease but was still present in the laboratory. Recent work performed in his laboratory allowed the identification of the first signaling pathway by which thyroid hormones control neurite outgrowth.

Numerous investigators trained by Jean can now be found in leading endocrine laboratories around the country and, indeed, around the world.
Jean was a fine physician and many patients were referred to him at the CHU Laval from different hospitals. Jean always was a warm and thoughtful physician for his patients and remained in close touch with them over the years. He was also an international expert in the field of thyroid hormones and he his opinion was often sought for.
Jean’s outstanding accomplishments were recognized by numerous organizations and led to him receiving widespread recognitions and awards. Some examples include his nomination for the Nobel prize of Medicine in 1982 at 42 yrs of age, The Ross Award in 1976 (the American Academy of Pediatric), the Van Meter-Armour Award in 1980 (American thyroid Association), Poulenc Santé Pediatric Award in 1987, The Manning award in 1988, the 125th anniversary medal of Canadian Confederation in 1992, the Wallac Robert Guthrie Award in 1999 (From the International Society for Neonatal Screening). He was also received member of the Order of Canada in 1988 and member of the National Order of Quebec in 2000.

Despite his many accomplishments and widespread recognitions nationally and internationally as a leading scientist who made pioneering contributions in the field of thyroid hormones, Jean remained a modest man. He always declined to apply for a patent for the neonatal blood test for congenital hypothyroidism that he developed because he considered his discovery as being a part of the public domain. In remembering Jean Dussault, we should focus own his personal example as a physician-scientist who could be intellectually rigorous and highly productive, while at the same time most compassionate and gentle in his manner towards all.

Dr Jack Puymirat, MD, PhD
Director of the Laboratory of Human Genetics
CHU Laval Research Center
2705 Blvd Laurier,
Sainte-Foy, Qc, G1V 4G2, Canada

Jean-Louis Dhondt, MD
President
International Society for Neonatal Screening