WRN and osteosarcoma: Patients with Werner syndrome present with premature aging, bilateral cataracts, short stature, osteoporosis, and hypogonadism.149 It is more commonly seen in the Japanese population and is usually caused by mutations in the WRN gene, which encodes a RecQ Helicase.133 This genetic mutation predisposes these patients to malignancy, often including thyroid neoplasms (16.7% of cases), but also soft-tissue sarcomas (10.1%) and osteosarcomas (7.7%).150 When osteosarcoma does develop, it is often in unusual locations such as the foot, ankle, or patella.133