Updates for c.274-6T>C:
2024-10-14 Class updated from VUS1 to non disease-causing
2024-12-09 Variant classified as non-disease-causing on the basis of epidemiological data (in particular high frequency in the general population), the number and type of diagnosis for patients reported in CFTR-France and functional data




Variant NM_000492.4:c.274-6T>C


Variant details:
Name NM_000492.4:c.274-6T>C
Protein name NP_000483.3:p.(=)
Genomic name (hg19)     chr7:g.117170947T>C    UCSC    
Genomic name (hg38) chr7:g.117530893T>C    UCSC
#Exon/intron intron 3
Legacy Name 406-6T>C
Class non disease-causing
WT sequence ATTTAATTTCTCTGTTTTTCCCCTT T TGTAGGAAGTCACCAAAGCAGTACA
Mutant sequence ATTTAATTTCTCTGTTTTTCCCCTT C TGTAGGAAGTCACCAAAGCAGTACA

Other databases:

Not found		dbSNP
no rs







Pathogenicity predictors:

Not found

Functional studies:


Reference PMID Splicing mRNA level Maturation Localization Channel fonction (Cl-) Bicarbonate
Raynal et al, 2013 23381846 ✓
Giorgi et al, 2015 25781545 ✓


« ✓ » indicates the type of analysis performed and not the results



No patient found in CFTR-NGS catalogue


6 patients carrying this variant are reported in CFTR-France:

TOTAL NUMBER OF PATIENTS 6
Asymptomatic compound heterozygote 2
CFTR-RD4
  • CBAVD  2
  • CRS-NP  2




Color code:   non disease-causing <   likely benign <   VUS <   likely pathogenic <   disease-causing

Detailed genotypes:
Phenotype Patient ID Variant status Additional variants
CRS-NP 3234heterozygote
CRS-NP 3268heterozygote
Asymptomatic compound heterozygote 4641heterozygoteCF-causing- Undef
Asymptomatic compound heterozygote 5167heterozygotevarying clinical consequence - Trans
CBAVD 4333heterozygotevarying clinical consequence- Undef
non-CF- Undef
CBAVD 4487heterozygoteVUS2- Undef


Color code:   non disease-causing <   likely benign <   VUS <   likely pathogenic <   disease-causing



            CFTR variants are clustered into five groups (click here for more details about the classification of variants):
  • CF-causing: when in trans with another CF-causing mutation, will result in CF.
  • CFTR-RD causing: when in trans with a CF-causing mutation, will result in CFTR-related disorders (CFTR-RD) such as chronic pancreatitis, bronchiectasis, CRS-NP (chronic rhinosinusitis with or without nasal polyposis) or CBAVD (congenital absence of vas deferens), according to Bombieri C et al., 2011.
  • Varying clinical consequence: when in trans with another CF-causing mutation, can either result in CF or in a CFTR-RD.
  • Non disease-causing: when in trans with a CF-causing mutation, will not cause CF, nor CFTR-RD.
  • VUS (Variant of unknown clinical significance): unclassified because of insufficient data.



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