Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Lesch-Nyhan Syndrome ?
    ### Response:
    Lesch-Nyhan syndrome (LNS) is a rare, inherited disorder caused by a deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT). LNS is an X-linked recessive disease-- the gene is carried by the mother and passed on to her son. LNS is present at birth in baby boys.
    