PIK3CA-Related Overgrowth Spectrum (PROS)

PROS, or PIK3CA‑Related Overgrowth Spectrum, is a group of rare, non‑inherited medical conditions that can cause certain parts of a child’s body to grow larger or differently than expected. These differences happen because of a change—called a somatic mutation—in the PIK3CA gene. This change occurs after a baby begins developing, which means it is not passed down from parents.

Children with PROS may have areas of the body that grow unevenly or faster than others. This can include skin, bones, fat or blood vessels. Every child is unique, so the symptoms and the amount of overgrowth can vary widely.

Some of the key diagnoses within PROS include:

• CLOVES Syndrome
• Klippel–Trenaunay Syndrome
• Fibroadipose Vascular Anomaly (FAVA)
• Macrodactyly
• Hemihyperplasia

Because PIK3CA‑Related Overgrowth Spectrum (PROS) includes several different conditions, the symptoms can look very different from child to child. Still, there are some common signs families and doctors may notice.

Children with PROS may experience:

• Larger‑than‑usual fingers or toes (sometimes just one or two)
• Uneven or faster growth in certain parts of the body—this may affect muscles, fat, bones or even internal organs
• A curved spine (scoliosis) caused by uneven growth
• Blood vessel differences, called vascular malformations, which may appear as unusual veins, birthmarks or swelling
• Lymphatic malformations, which can cause fluid‑filled areas under the skin

These symptoms are often visible at birth or early in childhood, and the areas of overgrowth may become more noticeable as a child grows.

In addition to the physical symptoms, it’s important to remember that PROS can also affect a child’s emotional well‑being, leading to feelings of stress, anxiety or depression.

Because PROS can affect different parts of the body, care is usually personalized.

Children with PROS may receive:

• Targeted medications: These are newer treatments designed to act on the specific genetic pathway affected in PROS. They can help slow or reduce abnormal tissue growth and may ease symptoms like pain or swelling
• Surgery: In some cases, surgery may be recommended to remove or reduce overgrown tissue, improve movement or address problems with blood vessels
• Multidisciplinary care: Children often benefit from a team of specialists—such as pediatricians, geneticists, surgeons, physical therapists and mental‑health professionals—who work together to support the child’s medical and emotional needs

Every child’s treatment plan is different, and families work closely with their healthcare team to decide what options will help their child thrive.