2631
Sequencing of the exon from the CVS , the predicted - carrier mother , and the obligate - carrier grandmother revealed an A - to - C change at nucleotide 541 in the two women but not in the fetus .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease 
Text: {0} 
Answer:
 None