Table 1.

Haplotype and diplotype distribution observed among concordant and discordant cystic fibrosis F508del homozygous sibling pairs for markers rs152730, rs8044970, rs63982, rs152745, rs152740.

	Freq. among 14 discordant pairs	Freq. among 23 concordant pairs
rs152730–rs8044970–rs63982–rs152745–rs152740 haplotype
TTAGA	0.839	0.599	Pcorr = 0.0397
GTCAT	0.051	0.185
GGAAT	0.036	0.129
Other pooleda	0.074	0.087

rs152730–rs8044970–rs63982–rs152745–rs152740 haplotype
TTAGA/TTAGAb	0.714	0.400	Pcorr = 0.049920
TTAGA/GTCAT	0.071	0.201
TTAGA/GGAAT	0.071	0.127
GGAAT/GGAATb	0.000	0.020
GTCAT/GTCATb	0.000	0.059
Other pooled	0.144	0.193

^aFour rare haplotypes (Freq. < 0.05) were observed among discordant pairs, 8 rare haplotypes (Freq. < 0.05) were observed among concordant pairs.

^bTo identify all genetic variants associated with intrapair discordance on the genomic fragment rs12730–rs152740, the entire 8000 bp genomic fragment was compared by Sanger re-sequencing for three homozygotes for TTAGA, two homozygotes for GGAAT and one homozygote for GTCAT (see Table 2).