Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the symptoms of Factor V Leiden thrombophilia ?
    ### Response:
    What are the signs and symptoms of factor V Leiden thrombophilia? Individuals affected by factor V Leiden thrombophilia have an increased risk of developing blood clots. The severity of factor V Leiden thrombophilia is extremely variable. Many individuals with the factor V Leiden allele never develop a blood clot.
    