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Irene Ayako Uchida

Photograph of Irene Ayako Uchida

(1917- )



Cytogenetic scientist specializing in Down Syndrome research

Dr. Irene Uchida was one of the first Canadian scientists to work in the field of cytogenetics, the study of chromosomes. She has received national and international recognition for her research on the effects of radiation on human chromosomes. Dr. Uchida's work in diagnosing and studying the causes of Down syndrome (formerly Down's syndrome) in the 1960s alerted medical science to a possible connection between radiation and birth defects. Her accomplishments are all the more remarkable because they were achieved despite many adversities in her personal life.

Irene was born in Vancouver, British Columbia in 1917. Her Japanese-born parents named her Ayako, which means 'splendid' in Japanese. One of five children, Ayako was an outgoing and popular teenager who was given the name Irene by her piano teacher, who found the Japanese name difficult to pronounce. Irene enjoyed music and played the organ, piano and violin for the United Church. Upon graduation from high school, she studied English literature at the University of British Columbia for two years. Irene interrupted her studies to join her mother and sisters who were visiting in Japan but, although they were all planning on returning to Canada, only Irene was able to catch a ship out of Japan prior to the Japanese attack on Hawaii in December 1941.

The subsequent unchecked advance of the Japanese forces created fear in British Columbia that an invasion of the Pacific coast was imminent and that the resident Japanese minority was a threat to Canada's security. In 1942, along with over 20,000 other members of the Japanese-Canadian community, Irene Uchida and the rest of her family still in Canada were forced to leave their home. The Canadian government relocated them to an internment camp at Christina Lake in the interior of British Columbia. Because of her university education, Uchida was asked to be the principal of a school for children of internees in Lemon Creek, British Columbia. She willingly took on this role of teacher under very difficult conditions. Uchida's life changed again when her father chose to be reunited with his wife and daughters in Japan as part of an exchange of Japanese Canadians for Allied prisoners of war and the government prohibited all Japanese Canadians from returning to Vancouver.

In 1944 the United Church offered Uchida a place to stay and support to continue her education at the University of Toronto. She earned a Bachelor of Arts degree from the University of Toronto in 1946 with the intention of taking a Master's degree in social work. However, with the encouragement of one of her professors, she decided to pursue a career in genetics with the result that in 1951 she completed her PhD in human genetics and began working at the Hospital for Sick Children in Toronto. Her work there involved the study of twins and children with Down syndrome, congenital heart diseases and other abnormalities. In 1960 she was appointed Director of the Department of Medical Genetics at the Children's Hospital in Winnipeg, Manitoba and began teaching at the University of Manitoba.

At that time, the most common of all severe birth abnormalities was Down syndrome. As research already indicated that Down syndrome was the result of a genetic abnormality and that radiation could cause these abnormalities, Dr. Uchida carried out two studies in Manitoba to determine if there was a connection between large doses of maternal radiation and Down syndrome births. After extensive investigation, Dr. Uchida found evidence that maternal exposure to abdominal x-rays increased the risk of birth defects in subsequent pregnancies. In later studies, it was found that damaged chromosomal material from the father also causes Down syndrome.

Dr. Uchida continued her research in England and the United States and founded the Cytogenetics Laboratory at McMaster University in Hamilton, Ontario in 1970. Scientific and government organizations both inside and outside of Canada recognized her expert knowledge in genetics. Among other responsibilities, she was the President of the American Society of Human Genetics in 1968, a member of the Science Council of Canada from 1970 to 1973, a member of the Advisory Committee on Genetic Services for Ontario in 1979, a consultant to the American Board of Medical Genetics in 1980 and a member of the Canadian College of Medical Geneticists from 1980 to 1984.

Over the course of her career Dr. Uchida has published more than ninety-five scientific papers and received numerous awards. Some of her Canadian awards are:

  • Woman of the Year, Winnipeg, Manitoba, 1963
  • Woman of the Century 1867-1967 for Manitoba, 1967
  • Queen Elizabeth II Speaker, Winnipeg, Manitoba, 1971
  • 1000 Canadian Women of Note from 1867-1967, 1983
  • Officer of the Order of Canada, 1993
  • Founder's Award, Canadian College of Medical Geneticists, 1995
  • Honorary Doctor of Science, University of Western Ontario, 1996

Today, Dr. Uchida lives in Hamilton and is a professor emeritus of the Department of Pediatrics and Pathology at McMaster University. She maintains an interest in research into the causes of birth defects and works with families of Down syndrome children.


Field, Dennis. — Science, process and discovery. — [Don Mills, Ontario] : Addison-Wesley, 1985. —  Chapter 27, "Down's syndrome and radiation : the work of Dr. Irene Uchida". — P. 175-182

Shell, Barry. — Great Canadian scientists. —  Victoria : Polestar Book Publishers, c1997. —  P. 116-121.  —  Also available online :

Uchida, I.A. ; Ray, M.  —  "Mail-order chromosome analysis".  —  Canadian Medical Association journal.  —  Vol. 94, no. 13 (March 26, 1966). — P. 649-650

Uchida, I.A. et al. — "Maternal radiation and chromosomal aberrations." — Lancet. — (November 16, 1968). — P. 1045-1049

Uchida, I.A. et al. — "Molecular studies of parental origin and mosaicism in 45,X conceptuses". — Human genetics. — Vol. 89, no. 6 (August 1989). — P. 647-652

Uchida, I.A. ; Freeman, V.C. — "Trisomy 21 Down syndrome. Parental mosaicism". — Human genetics. — Vol. 70, no. 3 (1985). — P. 246-248

Watada, Terry. — Seeing the invisible : the story of Dr. Irene Uchida. — Toronto : Umbrella Press, 1997. — 30 p.

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