Table 1.
Occurrence of meconium ileus (MI) in cystic fibrosis: linkage analysis with the 19q13 region (Zielenski et al. 1999)
| Sibpairsa | IBD=0 | IBD=1 | IBD=2 | Total | Conformity test chi2 (p-value)b |
|---|---|---|---|---|---|
| both MI | 0 (0%) | 3 (42.8%) | 4 (57.2%) | 7 | 4.7 (0.09) |
| neither MI | 22 (19.6%) | 59 (52.7%) | 31 (27.7%) | 112 | 4.8 (0.41) |
| discordant | 20 (60.6%) | 11 (33.3%) | 2 (6.1%) | 33 | 23.3 (8.7 10−6) |
| Total | 42 (27.6%) | 73 (48.1%) | 37 (24.3%) | 152 | 0.6 (0.75) |
a
152 sibpairs homozygous for the DeltaF508 mutation of the CFTR gene were sampled and grouped together depending on whether both sibs had a MI, none had a MI or were discordant for MI. The number of sibpairs sharing 0, 1 or 2 alleles identical by descent (IBD=0, 1 or 2) are reported with the respective proportions in parentheses.
b
Results of the test of conformity of the observed IBD distribution with the expected proportions under the null hypothesis of no linkage (1/4, 1/2, 1/4)