A Journey of Discovery Begins Before Birth

In Singapore, baby Cassie Chow's life was marked by an unusual beginning—her mother Lynnette Tay discovered during pregnancy scans that Cassie was set to enter the world with an enlarged left leg. Immediately after her birth, Cassie was placed in the neonatal intensive care unit for careful monitoring due to this peculiar limb size difference.

A Rare Diagnosis After a Lengthy Search

Despite her vital signs being normal, Cassie bore large port-wine stains on her skin, leading to puzzled doctors. Lynnette recalls, "The paediatrician was unsure of what was going on, but it seemed to be a rare condition." After extensive tests and an MRI scan at just two weeks old, a clearer picture was still elusive.

It wasn't until she turned one that Cassie was diagnosed with PIK3CA-Related Overgrowth Spectrum (PROS)—a rare genetic mutation affecting approximately one in 20,000 children. Biopsies confirmed the diagnosis, revealing how the condition leads to significant overgrowth or malformations across various body tissues, including muscles and blood vessels.

Understanding the Mutation: Not Hereditary

Dr. Mark Koh, who oversees dermatology at KK Women’s and Children’s Hospital, explained that PROS is a somatic mutation, occurring after conception when specific DNA changes arise in particular tissues. These mutations are mosaic, meaning not all body cells carry the mutation.

A Multi-Disciplinary Approach to Care

At KK Hospital, about three to four new PROS cases are identified each year. Dr. Koh describes how such cases often present at birth with disproportionate limbs and accompanying skin conditions. Treatment typically requires a multi-disciplinary approach, combining various medical and therapeutic interventions. Sclerotherapy and surgical options may be necessary alongside physical therapy to aid mobility.

Cassie’s Bright Spirit Shines Through

Despite the challenges, Cassie’s spirited personality beams. Now five, she loves the simple joys of life, like playing with family and indulging in gummy treats. While her mother has meticulously prepared information guides for her teachers, they actively embrace Cassie’s unique journey together.

Preparing for the Future While Spreading Awareness

Looking ahead, Lynnette recognizes that transitioning to primary school may bring new challenges, but she remains optimistic. To further legitimate awareness of rare skin conditions, organizations like the Rare Skin Conditions Society (Singapore) will launch a book called *The Skin We Wear: A Photo Story Of Skin And Kin* on May 2, 2025.

With every moment, Cassie's journey inspires others to embrace individuality and foster inclusivity.