Table 1.

Frequencies of signature nucleotides identified in the 5'NCR of type 1 HCV strains isolated in South America^a

	Frequency of query nucleotides				Frequency of background nucleotides
Positionb:	107	243	247	248	107	243	247	248
Nucleotide:	A	A	T	C	G	G	C	T
Among query set:	0.947	0.947	0.947	0.947	0.053	0.053	0.053	0.053
Among background set 1:	0.000	0.421	0.000	0.000	1.000	0.579	1.000	1.000
Among background set 2:	0.000	0.316	0.105	0.105	1.000	0.684	0.895	0.895
Among background set 3:	0.158	0.368	0.000	0.000	0.842	0.632	1.000	1.000

^a Background sets 1, 2 and 3 are composed by type 1 HCV strains isolated in South America, Europe and North America, respectively.

^b Numbers refer to nucleotide sequence position relative to strain HCV1b sequence [14].