Table 4 Evaluation of the basic defect in individuals with homozygous CFTR mutation genotypes
Patient numberCFTR mutationValues within the range of
F508del homozygotesIntermediateNon-CF healthy controls
Sweat chloride*ICM†NPD‡ICM†NPD‡Sweat chloride*ICM†NPD‡
BasalAmilCl-freeBasalCl-freeBasalAmil
Out-of-frame deletion
1CFTRdele2,3(21 kb)XXXXX
Nonsense mutation
2R553XXXXXX
3R1162XXXXXX
4R1162XXXXXX
Splice-site mutation
51898+3 A-GXXXXX
63849+10 kb C-TXXXXX
73849+10 kb C-TXXXXX
In-frame deletion
8CFTRdele2(ins186)XXXXX
9CFTRdele2(ins186)XXXXX
10CFTRdele2(ins186)XXXXX
Missense mutation
11E92KXXXXX
12G314EXXXXX
13L997FXX
14W1098LXX
15M1101KXXXXX
16M1101KXXXXX
17M1101KXXXXX
  • Sibpairs: patients 3 & 4, 6 & 7, 9 & 10, 15, 16 & 17.

  • Consanguineous parents of patients: 1, 3–14

  • *Sweat chloride concentrations determined in Gibson–Cooke pilocarpine iontophoresis sweat tests.

  • †DIDS-insensitive cAMP-activatable chloride secretory responses in rectal suction biopsies as surrogate parameter for CFTR function.4 7

  • ‡NPD measurements of the basal PD (basal), the response to amiloride (amil) and the cumulative response to chloride-free solution plus isoprotenerol (Cl -free).