rs201759207

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1PP2

The NM_000492.4(CFTR):​c.2770G>A​(p.Asp924Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000141 in 1,613,916 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D924H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00015 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00014 ( 0 hom. )

Consequence

CFTR
NM_000492.4 missense

Scores

7
8
4

Clinical Significance

Uncertain significance reviewed by expert panel P:1U:12O:1

Conservation

PhyloP100: 9.76

Publications

17 publications found
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 Gene-Disease associations (from GenCC):
  • cystic fibrosis
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, Orphanet
  • congenital bilateral absence of vas deferens
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • hereditary chronic pancreatitis
    Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 23 uncertain in NM_000492.4
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 197 curated pathogenic missense variants (we use a threshold of 10). The gene has 46 curated benign missense variants. Gene score misZ: -3.1397 (below the threshold of 3.09). Trascript score misZ: -1.0868 (below the threshold of 3.09). GenCC associations: The gene is linked to hereditary chronic pancreatitis, cystic fibrosis, congenital bilateral absence of vas deferens.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CFTRNM_000492.4 linkc.2770G>A p.Asp924Asn missense_variant Exon 17 of 27 ENST00000003084.11 NP_000483.3 P13569-1A0A024R730

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CFTRENST00000003084.11 linkc.2770G>A p.Asp924Asn missense_variant Exon 17 of 27 1 NM_000492.4 ENSP00000003084.6 P13569-1

Frequencies

GnomAD3 genomes
AF:
0.000151
AC:
23
AN:
152164
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000385
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000676
AC:
17
AN:
251412
AF XY:
0.0000810
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000114
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000140
AC:
204
AN:
1461752
Hom.:
0
Cov.:
32
AF XY:
0.000143
AC XY:
104
AN XY:
727184
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33468
American (AMR)
AF:
0.0000224
AC:
1
AN:
44698
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.000126
AC:
5
AN:
39694
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.000172
AC:
191
AN:
1111930
Other (OTH)
AF:
0.0000828
AC:
5
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.471
Heterozygous variant carriers
0
12
25
37
50
62
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.000151
AC:
23
AN:
152164
Hom.:
0
Cov.:
33
AF XY:
0.000135
AC XY:
10
AN XY:
74326
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.000385
AC:
2
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000294
AC:
20
AN:
68018
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.468
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.000143
Hom.:
0
Bravo
AF:
0.0000982
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.0000741
AC:
9
EpiCase
AF:
0.00
EpiControl
AF:
0.000178

ClinVar

Significance: Uncertain significance
Submissions summary: Pathogenic:1Uncertain:12Other:1
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

Cystic fibrosis Pathogenic:1Uncertain:4Other:1
Mar 13, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.D924N variant (also known as c.2770G>A), located in coding exon 17 of the CFTR gene, results from a G to A substitution at nucleotide position 2770. The aspartic acid at codon 924 is replaced by asparagine, an amino acid with highly similar properties. This variant was detected in two individuals diagnosed with cystic fibrosis; however, additional genotype and phenotype information was not provided (Alonso MJ et al. Ann. Hum. Genet., 2007 Mar;71:194-201; Zitkiewicz E et al. PLoS ONE, 2014 Feb;9:e89094). In one French individual, the p.D924N variant was reported in cis with p.F508del (Baatallah N et al. Hum. Mutat., 2018 Apr;39:506-514). This variant was also identified in trans with a 5T variant in an individual with recurrent pancreatitis (Koyano S et al. Pancreas, 2010 Jul;39:686-7). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on available evidence to date, the clinical significance of this alteration remains unclear. -

Dec 20, 2019
CFTR2
Significance:Uncertain significance
Review Status:reviewed by expert panel
Collection Method:research

- -

Jan 29, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 924 of the CFTR protein (p.Asp924Asn). This variant is present in population databases (rs201759207, gnomAD 0.01%). This missense change has been observed in individual(s) with CFTR-related conditions (PMID: 20562583). ClinVar contains an entry for this variant (Variation ID: 53565). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CFTR protein function with a positive predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Nov 27, 2017
Counsyl
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

-
ClinVar Staff, National Center for Biotechnology Information (NCBI)
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

- -

Sep 05, 2022
Institute of Human Genetics, University of Leipzig Medical Center
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:curation

This variant was identified in 1 patient with a clinically confirmed diagnosis of cystic fibrosis. The variant was classified in the context of a project re-classifying variants in the German Cystic Fibrosis Registry (Muko.e.V.). Link: https://www.muko.info/angebote/qualitaetsmanagement/register/cf-einrichtungen/mukoweb. Criteria applied: PM3_STR, PM2_SUP, PM5_SUP, PP3, PS3_SUP, PP4 -

not provided Uncertain:6
Jan 19, 2021
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 01, 2022
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 27, 2017
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The CFTR c.2770G>A; p.Asp924Asn variant (rs201759207) has been reported in cystic fibrosis patients, but its clinical significance was not determined (Alonso 2006, Zietkiewicz 2014). It is listed in ClinVar (Variation ID: 53565) and observed in the general population at an overall frequency of 0.009% (25/277152 alleles) in the Genome Aggregation Database. The aspartic acid at codon 924 is highly conserved, but computational algorithms (PolyPhen-2: probably damaging; SIFT: tolerated) are inconclusive on the variant's impact on the protein. Due to the limited information regarding this variant, its clinical significance cannot be determined with certainty. References: Alonso M et al. Spectrum of mutations in the CFTR gene in cystic fibrosis patients of Spanish ancestry. Ann Hum Genet. 2007; 71(Pt 2):194-201. Zietkiewicz E et al. CFTR mutations spectrum and the efficiency of molecular diagnostics in Polish cystic fibrosis patients. PLoS One. 2014; 9(2):e89094. -

-
Breakthrough Genomics, Breakthrough Genomics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

Dec 05, 2016
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 22, 2020
Mayo Clinic Laboratories, Mayo Clinic
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Feb 03, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: CFTR c.2770G>A (p.Asp924Asn) results in a conservative amino acid change located in the ABC transporter type 1, transmembrane domain (IPR011527) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. Consensus agreement among computation tools predict no significant impact on normal splicing. In a minigene assay this variant has been shown to cause exon skipping (Baatallah_2018), however, the exact in-vivo consequences of this finding are not known. The authors speculated that this variant when present in cis with p.Phe508del could result in a reduced amount of full length CFTR, hence reducing the amount of CFTR-p.Phe508del targeted by corrector/potentiator treatment. The variant allele was found at a frequency of 6.8e-05 in 251412 control chromosomes (gnomAD). c.2770G>A has been reported in the literature in individuals affected with Cystic Fibrosis (CF), CF- related disorders as well as pancreatic cancer (e.g. Alonso_2007, deCid_2010, Koyano_2010, Zietkiewicz_2013, Guan_2018, Tamura_2019, Claustres_2017). These reports however, do not provide unequivocal conclusions about association of the variant with Cystic Fibrosis. CFTR2 database also report this variant as variant of uncertain significance. Co-occurrences with other pathogenic variant(s) have been reported (Baatallah_2018, CFTR c.1521_1523del, p.F508del), providing supporting evidence for a benign role. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect resulted in approximately 33% of normal chloride channel conductance relative to wild type (Bihler_2024). The following publications have been ascertained in the context of this evaluation (PMID: 19812525, 17331079, 24586523, 25735457, 20562583, 28603918, 29997923, 29669919, 31883651, 29271547, 38388235). ClinVar contains an entry for this variant (Variation ID: 53565). Based on the evidence outlined above, the variant was classified as uncertain significance. -

CFTR-related disorder Uncertain:1
Jun 23, 2018
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.83
BayesDel_addAF
Benign
-0.050
T
BayesDel_noAF
Uncertain
0.020
CADD
Pathogenic
29
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.49
T;.;.;T;.
Eigen
Pathogenic
0.74
Eigen_PC
Pathogenic
0.77
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.96
D;D;D;D;D
M_CAP
Pathogenic
0.66
D
MetaRNN
Uncertain
0.54
D;D;D;D;D
MetaSVM
Uncertain
0.63
D
MutationAssessor
Uncertain
2.5
M;.;.;.;.
PhyloP100
9.8
PrimateAI
Uncertain
0.53
T
PROVEAN
Benign
-0.47
N;.;.;N;.
REVEL
Uncertain
0.53
Sift
Benign
0.040
D;.;.;D;.
Sift4G
Pathogenic
0.0010
D;.;.;D;.
Polyphen
1.0
D;.;.;.;.
Vest4
0.85
MVP
1.0
MPC
0.0076
ClinPred
0.20
T
GERP RS
5.8
Varity_R
0.79
gMVP
0.81
Mutation Taster
=16/84
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs201759207; hg19: chr7-117243698; COSMIC: COSV50095194; COSMIC: COSV50095194; API