605
An allele - specific polymerase chain reaction system designed to detect exclusively only one of the normal and mutant alleles indicated that all the four patients were homozygous for the mutation in exon 4 and that the parents of patient 2 were heterozygous .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease 
Text: {0} 
Answer:
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