Segmental overgrowth syndrome due to an activating PIK3CA mutation identified in affected muscle tissue by exome sequencing.

Mosaic PIK3CA-mutations have been described in an increasing number of overgrowth syndromes. We describe a patient with a previously unreported segmental overgrowth syndrome with the mutation, PIKCA3 c.3140A>G (p.His1047Arg) in affected tissue diagnosed by exome sequencing. This PIK3CA-associated segmental overgrowth syndrome overlaps with CLOVES syndrome and fibroadipose hyperplasia but is distinct from each of these entities.