Summary
PIK3CA-related overgrowth spectrum (PROS) includes a group of genetic disorders that leads to overgrowth of various body parts due to changes (variants) in the gene PIK3CA. This gene is involved in making a protein that helps regulate cell growth, division and survival. A broad array of disorders falls within this spectrum, with some overlap of symptoms between the different disorders. Syndromes within the spectrum may also overlap genetically, meaning they may share specific PIK3CA gene variants in cells in the areas of the body that are affected. Since PIK3CA variants in these disorders are not present in all cells, only certain areas of the body are overgrown, ranging from isolated digits to whole limbs, trunk, or brain. Different tissues may be involved individually or in combination such as fat, muscle, bone, nerve, brain and blood vessels. Gene variants that cause these disorders are not passed down from parent to child but instead result from changes to genes during development in the womb. Symptoms associated with these disorders can be present at birth (congenital) or appear later in early childhood. Overgrowth may stop in childhood or continue into adulthood.
