510
Administration of drugs that inhibit adenine phosphoribosyltransferase ( APRT ) in HPRT - deficient mice has produced the suggestion that deficiency of APRT in combination with HPRT - deficiency in mice may lead to self - mutilation behavior [ C . L . Wu and D . W . Melton ( 1993 ) Nature Genet . 3 , 235 - 240 ] .
 Disease: HPRT - deficient; Disease: deficiency of APRT; Disease: HPRT - deficiency
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease 
Text: {0} 
Answer:
 Disease: HPRT - deficient; Disease: deficiency of APRT; Disease: HPRT - deficiency