Irene Ayako Uchida

Genetics

World-famous Down syndrome researcher

"Do your best no matter what you do even if it's a menial job."

Irene Uchida has been asked to join the morning hospital rounds at Children’s Hospital in Winnipeg, Manitoba. It’s around 1960. She’s talking about patients who have the symptoms of trisomy of chromosome 18 — that is, three number 18 chromosomes instead of the normal two. A doctor named Jack Sinclair raises his hand and says, “Hey, I think we have one on the fourth floor.”

He takes her up to the ward right away. They get a blood sample from the patient and add some anti-clotting agent. Uchida immediately goes to work to identify the chromosomes. Diagnosing trisomy by actually looking at a patient’s chromosomes is something very new, and it has never been done by anybody in Winnipeg — or even in Canada.

She takes the blood to the cytology lab, a place in the hospital for examining cells. The lab has the vinegary smell of acetic acid. Low tables by the windows have lots of microscopes, with technicians in white lab coats seated at most of them. Along the opposite wall, a few people are preparing samples and slides.

First Uchida lets the red blood cells settle in the vial, then she takes the white blood cells off the top with a pipette, a long glass tube that is used to suck up small amounts of liquid. She transfers them to a small glass container containing a medium in which they grow and multiply for three days, inside an incubator. Then she takes out the liquid and centrifuges it down. A centrifuge is a device that spins test tubes around super-fast to force all the heavy stuff to the bottom, leaving lighter cells and liquid at the top. She “fixes” the cells with acetic acid solution, and drops them onto a glass slide so that the cells break and spill out their chromosomes. She stains the material on the slide with a dye, puts it under the microscope and looks for the chromosomes — long, twisty, banded strands of protein and DNA. She finally does find three number 18 chromosomes instead of the normal two, confirming the diagnosis. This cytogenetic analysis is a first for Winnipeg and Canada.


As a young scientist ...

At the University of British Columbia (UBC) Irene Uchida was a member of the Japanese Students Club and a reporter for a weekly Japanese-Canadian newspaper. During World War II she was active in the group Japanese Canadian Citizens for Democracy. Because Canada was at war with Japan and feared an invasion, it was a period of great anxiety for the 23,000 people of Japanese heritage who were uprooted from their homes on the West Coast by an order-in-council of the federal government in 1942 and had their possessions and properties seized.

Uchida was forced to stop her education at ubc and leave her home in Vancouver. She and her family were taken to an internment camp at Christina Lake in British Columbia’s Kootenay region, where she became principal of the largest internment-camp school, at nearby Lemon Creek. She became known for her creative ideas. Two years later she was allowed to continue her education at the University of Toronto, graduating in 1946 with a bachelor of arts. She planned to take up social work, but one of her professors persuaded her to enter the field of genetics.

In 1951 Uchida received her doctorate in zoology and began her career as a research associate at the Hospital for Sick Children in Toronto. Her work in genetics focused on the study of twins, children with congenital heart diseases and those with a variety of other anomalies such as Down syndrome.

In 1959, while working with Drosophila (fruit fly) chromosomes at the University of Wisconsin, Uchida turned her attention to human chromosomes. When scientists in France discovered that Down syndrome patients had an extra chromosome (47 instead of 46), she decided to try to learn the cause of the extra chromosome. She continued her research in Winnipeg when she was appointed director of the Department of Medical Genetics at Children’s Hospital there, in 1960. In her first study of human chromosomes, Uchida found that there appeared to be an association between pregnant women who received X-rays and the occurrence of Down syndrome in their babies.

In 1969, with a Medical Research Council grant, she went as a visiting scientist to the University of London and to Harwell, England, to study a technique for analyzing the chromosomes of mouse eggs.

After returning to Canada, Uchida continued her research on the effects of radiation on humans and mice at the McMaster University Medical Centre in Hamilton, Ontario, as well as carrying out her teaching duties as a professor. She also initiated a Genetic Counselling Program at the McMaster Medical Centre. As director of the Cytogenetics Laboratory in Oshawa, Ontario, her responsibilities included the diagnosis of chromosome differences in patients with congenital abnormalities, developmental disabilities and other genetic conditions. In addition, Uchida helped diagnose irregularities in the chromosomes of fetuses. She has been invited to speak in many countries and is a member of various provincial, national and international scientific organizations.

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