Singapore Family’s Journey Highlights Advances in Genetic Testing for Cancer Prevention
A growing number of genetic conditions are now being screened for during IVF, offering hope to families like the Lees who carry the risk of passing on debilitating and life-threatening diseases. On October 31st, 2025, Singapore expanded the list of conditions eligible for pre-implantation genetic testing (PGT) to 169, including 13 severe genetic conditions, marking a significant step forward in preventative healthcare.
Facing a Family History of FAP
Felicia Lee, a 42-year-old homemaker in Singapore, knows all too well the weight of inherited disease. She was diagnosed with familial adenomatous polyposis (FAP) at the age of 12, a rare genetic condition affecting approximately one in 8,000 people. FAP causes the development of hundreds, or even thousands, of polyps in the colon and rectum, dramatically increasing the risk of colorectal cancer at a young age.
“I was about eight or nine when my father, who was then with the SAF, was deployed overseas for training,” Ms. Lee recalled. “He was unwell when he returned, which deeply worried my mother.” Subsequent tests revealed her father also had FAP, requiring surgery to remove part of his large intestine.
This diagnosis triggered cascade testing – screening family members for the genetic mutation – which ultimately revealed that Ms. Lee, her younger sister Alicia, and two cousins also carried the gene. According to Associate Professor Joanne Ngeow, who heads the Cancer Genetics Service at the National Cancer Centre Singapore, cascade testing is crucial “to enable early diagnosis, prevention and treatment before symptoms appear.”
The Genetic Root of the Problem
FAP is caused by mutations in the adenomatous polyposis coli (APC) gene, a tumor suppressor gene responsible for regulating cell growth. “If you carry the (mutated) gene, you are very likely to develop multiple polyps in your colon and are at a very high risk of (developing) colon cancer,” explained Professor Ngeow, who is also an associate professor of genomic medicine at the Nanyang Technological University’s Lee Kong Chian School of Medicine.
Ms. Lee experienced frequent bowel movements in her early teens, leading her to consult Associate Professor Tang Choong Leong, a senior colorectal surgeon at the Singapore General Hospital (SGH). A colonoscopy revealed “thousands of polyps…a few large ones that blocked three-quarters of the passage.” At 15, she underwent a prophylactic colectomy – the removal of part of her large intestine – to prevent the development of cancer.
The surgery initially required a temporary stoma bag, a surgically created opening in the abdomen to divert waste. “I was told before the surgery that I would have to have a stoma bag for at least three months,” Ms. Lee said. “At that time, I did not really know what it meant. I was not too worried.” She adapted remarkably well, even concealing the bag under her uniform while attending school. Dietary adjustments – eliminating spicy foods and dairy – and modifications to her physical activity were the only significant lifestyle changes. A second operation, performed after a month, successfully reconnected her intestine, restoring normal bowel function.
IVF and the Promise of a Healthy Future
Knowing she had a 50 percent chance of passing the FAP mutation to her children, Ms. Lee and her husband, Cedric Ng, opted for in-vitro fertilisation (IVF). “IVF provided a platform for genetic screening,” Ms. Lee explained, “and we went through pre-implantation genetic testing to ensure that our baby will not have the FAP defect before the embryo was implanted.”
The couple underwent two rounds of IVF before welcoming their daughter, Phoebe, now one year old. Ms. Lee’s pregnancy required careful monitoring at SGH, with her colorectal doctors on standby. She delivered via caesarean section and experienced a temporary intestinal obstruction, requiring a week-long hospital stay.
“Going through all those challenges makes our daughter all the more precious,” she said.
Expanding Access to Genetic Screening
The expansion of PGT to 169 conditions reflects a growing understanding of the role genetics plays in disease. Hereditary cancers account for approximately 5 to 10 percent of all cancer cases in Singapore. While current screening guidelines recommend starting regular colorectal cancer screenings at age 50 for the general public, Professor Ngeow emphasizes the importance of earlier and genetic testing for high-risk individuals. “But individuals at high risk – meaning that they have a family member who has colon cancer, or if they have colon cancer under the age of 50 – should come in for a discussion on whether they need genetic (testing). We will also follow up with what we call cascade testing of the rest of the family.”
Colorectal cancer, often called the “silent killer” due to its lack of early symptoms, is the leading cancer in men and the second most common in women in Singapore, with approximately 1,200 new cases diagnosed annually. The Lees’ story underscores the power of proactive genetic testing and the hope it offers to families facing the threat of inherited diseases.
