Pfeiffer syndrome is a rare genetic disorder caused by mutations in the FGFR1 or FGFR2 genes. It is characterized by the premature fusion of certain skull bones, leading to an abnormal head shape. Individuals with this condition may also experience broad, short thumbs and toes, as well as other skeletal abnormalities. Symptoms can vary widely among affected individuals, but common features include a high forehead, wide-set eyes, and hearing loss. Treatment often involves surgery to correct skull shape and improve appearance, along with ongoing medical care to address any associated health issues.