Due to the presence of bruises without trauma, acquired von Willebrand syndrome secondary to primary hypothyroidism was suspected, and vWF levels were measured using an ELISA (Animal Health Diagnostic Center, Cornell University, Ithaca, NY, USA), indicated that a vWF level of 30% (reference range, 70–180%) was into the “carrier range” (< 50%), suggesting an elevated risk of abnormal bleeding and potential transmission of vWD. The gene discussed is VWF; the disease is Primary hypothyroidism.