Uchida was born on April 8, 1917 in Vancouver, British Columbia, Canada. She was a brilliant child, playing both the violin, the organ, and the piano and was often described as a "social" and "outgoing" individual. Unfortunately, Uchida lost her best friend from a tragic car accident as well as her sister, Sachi, from tuberculosis. Due to this, Irene wanted to pursue a field in which she could help people throughout her life. At first, because her father owned two Japanese bookstores in Vancouver, it seemed fitting for Irene to pursue her bachelor's for English literature. However, the Pearl Harbor attack in 1941 disrupted her studies. The fear within this period would push Irene and her family into an internment camp at Christina Lake, British Columbia. Her knowledge would lead her to become a principal for a school for children internees during this time. She would later finish her degree at the University of Toronto with the sponsorship of the United church in Vancouver. Despite initially wanting to pursue a masters in social work, she was encouraged by her professors to pursue a career in genetics. Thus, she completed her P.h.D. in zoology at the university of Toronto in 1951 and would later work at the hospital for sick children, where she studied twins and children with down syndrome. In 1960, she would become the director of medical genetics in 1960, developing a clinical test for trsiomy-18. She would later found the Cytogenetics Laboratory at McMaster University in Hamilton, Ontario, in 1970, and would teach in pediatrics and pathology unntil 1991 at the university. After a long battle with Alzheimer's disease, she would later die on July 30, 2013.

Uchida's discoveries had a significant impact in science as well as patient care. Through her investigation of Down Syndrome, she would uncover how complex genes and chromosomal abnormalities would come into play into the syndrome. Thanks to her studies, clinicians would use her method of detecting chromosomal abnormalities in a fetus. Additionally, her development of the use of fluorescent chromosome banding would allow future scientist to use that technique to study abnormalities in developmental genes. Uchida's contributions had a profound impact in the field of human genetics, in turn indirectly shaping modern clinical practice and improving individual's lives that are affected by genetic disorders.