Progressive osseous heteroplasia (POH), which is characterized by patches of dermal ossification during infancy and progressive heterotopic ossification of superficial and deep connective tissues such as muscles, tendons, and ligaments during childhood, was first described in 1994. POH is an extremely rare disorder; Kaplan et al. (1998) report 13 classic cases, and the International Fibrodysplasia Ossificans Progressiva Association (IFOPA, 1999) reports fewer than 36 known patients.