TableĀ 2

CFTR2 classification of CFTR variants

CF causing variantA variant expected to cause CF when present with another CF causing variant on a separate allele (one CF causing variant inherited from each parent)
Non-CF causing variantA variant not expected to cause CF
Individuals with one or more of this type of variant are unlikely to have CF
If a CF causing variant is present on a separate allele, a small number of individuals may develop CFTR-RD
Variant of varying clinical consequence (VVCC)A variant that may or may not result in CF when present with a CF causing variant on a separate allele (some individuals may develop CFTR-RD)
Variant of unknown significance (VUS)Variants where there is insufficient data to determine whether they are phenotypically disease causing or not

CFTR-RD: CFTR-related disorder. Adapted from [1, 3, 12].