Medical Mysteries is a series that spotlights rare diseases or unusual conditions.

SINGAPORE - She was only 12 when she was diagnosed with Familial Adenomatous Polyposis (FAP), a rare inherited condition that causes hundreds or thousands of polyps to form in the colon and rectum.

And when she turned 15, housewife Felicia Lee, now 42, had to have part of her colon removed.

FAP is a rare genetic condition, affecting about 1 in 8,000 people. It results in the development of hundreds and thousands of colon polyps – which are non-cancerous growths – significantly increasing the risk of colorectal cancer, often at an early age.

The condition is caused by mutations in the Adenomatous Polyposis Coli (APC) gene, which is a tumour suppressor gene that normally controls cell growth.

With a 50 per cent likelihood of a child inheriting the genetic mutation responsible for FAP from an affected parent, Ms Lee chose to conceive through in-vitro fertilisation (IVF). Hereditary cancer makes up about 5 to 10 per cent of all cases of cancer in Singapore.

“IVF provided a platform for genetic screening and we went through pre-implantation genetic testing to ensure that our baby will not have the FAP defect before the embryo was implanted,” she told The Straits Times.

Since Oct 31,

13 severe genetic conditions have been added

to a list of conditions approved for testing before couples decide to go ahead with the implantation of embryos in IVF, bringing the total number of conditions approved for pre-implantation genetic testing to 169.

Wearing a stoma bag to school

Ms Lee’s early diagnosis came about after her father was diagnosed with the same condition.