NM_000492.4:c.3469-17T>C

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_StrongBP6BS2_Supporting

The NM_000492.4(CFTR):c.3469-17T>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00085 in 1,612,446 control chromosomes in the GnomAD database, including 4 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00048 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00089 ( 4 hom. )

Consequence

CFTR
NM_000492.4 intron

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:7

Conservation

PhyloP100: 2.01

Variant links:

Genes affected

CFTR (HGNC:1884): (CF transmembrane conductance regulator) This gene encodes a member of the ATP-binding cassette (ABC) transporter superfamily. The encoded protein functions as a chloride channel, making it unique among members of this protein family, and controls ion and water secretion and absorption in epithelial tissues. Channel activation is mediated by cycles of regulatory domain phosphorylation, ATP-binding by the nucleotide-binding domains, and ATP hydrolysis. Mutations in this gene cause cystic fibrosis, the most common lethal genetic disorder in populations of Northern European descent. The most frequently occurring mutation in cystic fibrosis, DeltaF508, results in impaired folding and trafficking of the encoded protein. Multiple pseudogenes have been identified in the human genome. [provided by RefSeq, Aug 2017]

CFTR links:

ENSG00000083622 (HGNC:):

ENSG00000083622 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -6 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.82).

BP6

Variant 7-117627505-T-C is Benign according to our data. Variant chr7-117627505-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 53751.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Benign=2, Uncertain_significance=5}. Variant chr7-117627505-T-C is described in Lovd as [Benign].

BS2

High Homozygotes in GnomAdExome4 at 4 AR geneVariant has number of homozygotes lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CFTR	NM_000492.4 link	c.3469-17T>C		intron_variant	Intron 21 of 26	ENST00000003084.11	NP_000483.3	P13569-1A0A024R730

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11 link	c.3469-17T>C		intron_variant	Intron 21 of 26	1	NM_000492.4	ENSP00000003084.6		P13569-1

Frequencies

GnomAD3 genomes

AF:

0.000480

AC:

AN:

152166

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000241

Gnomad AMI

AF:

0.00439

Gnomad AMR

AF:

0.000524

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00290

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000529

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.000592

AC:

148

AN:

249920

Hom.:

AF XY:

0.000822

AC XY:

111

AN XY:

135080

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.0000582

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000547

Gnomad SAS exome

AF:

0.00327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000337

Gnomad OTH exome

AF:

0.000823

GnomAD4 exome

AF:

0.000888

AC:

1297

AN:

1460162

Hom.:

Cov.:

AF XY:

0.000979

AC XY:

711

AN XY:

726376

show subpopulations

Gnomad4 AFR exome

AF:

0.000180

Gnomad4 AMR exome

AF:

0.0000448

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000253

Gnomad4 SAS exome

AF:

0.00355

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000843

Gnomad4 OTH exome

AF:

0.000763

GnomAD4 genome

AF:

0.000479

AC:

AN:

152284

Hom.:

Cov.:

AF XY:

0.000551

AC XY:

AN XY:

74456

show subpopulations

Gnomad4 AFR

AF:

0.000241

Gnomad4 AMR

AF:

0.000524

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00290

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000529

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.000438

Hom.:

Bravo

AF:

0.000465

Asia WGS

AF:

0.000577

AC:

AN:

3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign:7

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:3Benign:2

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Aug 26, 2023

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The CFTR c.3469-17T>C variant has been reported in the published literature in individuals with cystic fibrosis (PMID: 7683952 (1993), 12815607 (2003), 28544683 (2017)) and CFTR-RD, including azoospermia (PMID: 20021716 (2009), 28456595 (2017)) as well as in unaffected individuals (PMID: 17890437 (2007)). The frequency of this variant in the general population, 0.0033 (100/30538 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using software algorithms for the prediction of the effect of nucleotide changes on splicing yielded predictions that this variant does not affect CFTR mRNA splicing . Based on the available information, we are unable to determine the clinical significance of this variant. -

Mar 15, 2018

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 20, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 16, 2022

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Also known as c.3601-17T>C, observed in individuals with cystic fibrosis, but additional information was not provided (Audrezet et al., 1993; Soltysova et al., 2018); In silico analysis supports that this variant does not alter splicing; This variant is associated with the following publications: (PMID: 26847993, 28456595, 20021716, 10439967, 17890437, 18685558, 23503723, 25797027, 28544683, 10923036, 12815607, 34426522, 7683952) -

Cystic fibrosis

Uncertain:1Benign:2

Nov 03, 2022

Ambry Genetics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Jul 26, 2021

Genome Diagnostics Laboratory, The Hospital for Sick Children

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 26, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified

Benign:3

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Sep 30, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: CFTR c.3469-17T>C alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 4/4 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00059 in 250506 control chromosomes, predominantly at a frequency of 0.0033 within the South Asian subpopulation in the gnomAD database, including 1 homozygote. This frequency is not significantly higher than estimated for a pathogenic variant in CFTR causing Cystic Fibrosis (0.00059 vs 0.013), allowing no conclusion about variant significance. c.3469-17T>C has been reported in the literature as non-informative genotypes (second allele and/or phase not specified) in cohorts of individuals affected with Cystic Fibrosis, diffuse bronchiectasis and azoospermia (e.g. Audrezet_1993, Claustres_2000, Scotet_2003, Gallati_2009, Soltysova_2018, Vaidyanathan_2022) but it was also reported in healthy controls (e.g. Bergougnoux_2015). These report(s) do not provide unequivocal conclusions about a penetrant association of the variant with fulminant Cystic Fibrosis. The variant was found to co-occur with two other deleterious CFTR variants (c.1393-1G>A and c.5T_TG12) in at-least one specimen tested at our laboratory. The phase of this variant was not determined, however it provides supporting evidence for a benign role. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 7683952, 25797027, 10923036, 18685558, 20021716, 28456595, 26847993, 17890437, 12815607, 28544683, 35857025, 23503723). ClinVar contains an entry for this variant (Variation ID: 53751). Based on the evidence outlined above, the variant was classified as likely benign. -

Congenital bilateral aplasia of vas deferens from CFTR mutation

Uncertain:1

Juno Genomics, Hangzhou Juno Genomics, Inc

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2_Supporting+PM3_Supporting -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.82

CADD

Benign

DANN

Benign

0.53

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over