7-117592246-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_000492.4(CFTR):ā€‹c.2079T>Gā€‹(p.Phe693Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000465 in 1,613,816 control chromosomes in the GnomAD database, with no homozygous occurrence. 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: š‘“ 0.00028 ( 0 hom., cov: 32)
Exomes š‘“: 0.000023 ( 0 hom. )

Consequence

CFTR
NM_000492.4 missense

Scores

9
10

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:10B:1

Conservation

PhyloP100: 0.0260
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.09189761).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
CFTRNM_000492.4 linkuse as main transcriptc.2079T>G p.Phe693Leu missense_variant 14/27 ENST00000003084.11 NP_000483.3 P13569-1A0A024R730

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
CFTRENST00000003084.11 linkuse as main transcriptc.2079T>G p.Phe693Leu missense_variant 14/271 NM_000492.4 ENSP00000003084.6 P13569-1

Frequencies

GnomAD3 genomes
AF:
0.000263
AC:
40
AN:
152120
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000966
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000723
AC:
18
AN:
248958
Hom.:
1
AF XY:
0.0000592
AC XY:
8
AN XY:
135192
show subpopulations
Gnomad AFR exome
AF:
0.000898
Gnomad AMR exome
AF:
0.0000579
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000330
GnomAD4 exome
AF:
0.0000226
AC:
33
AN:
1461578
Hom.:
0
Cov.:
32
AF XY:
0.0000124
AC XY:
9
AN XY:
727064
show subpopulations
Gnomad4 AFR exome
AF:
0.000866
Gnomad4 AMR exome
AF:
0.0000447
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.000276
AC:
42
AN:
152238
Hom.:
0
Cov.:
32
AF XY:
0.000282
AC XY:
21
AN XY:
74434
show subpopulations
Gnomad4 AFR
AF:
0.00101
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000305
Hom.:
0
Bravo
AF:
0.000314
ESP6500AA
AF:
0.000908
AC:
4
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.000107
AC:
13

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:10Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Cystic fibrosis Uncertain:4Benign:1
Uncertain significance, criteria provided, single submitterclinical testingCounsylMay 31, 2018- -
Uncertain significance, criteria provided, single submitterclinical testingMendelicsMay 28, 2019- -
Likely benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 24, 2024- -
Uncertain significance, criteria provided, single submitterclinical testingAmbry GeneticsMar 24, 2023The p.F693L variant (also known as c.2079T>G), located in coding exon 14 of the CFTR gene, results from a T to G substitution at nucleotide position 2079. The phenylalanine at codon 693 is replaced by leucine, an amino acid with highly similar properties. This alteration was observed in an individual with cystic fibrosis-like disease; however, a second CFTR alteration was not documented (Mutesa L et al. Chest, 2009 May;135:1233-42). This alteration was also identified in conjunction with p.F508del in an individual with pancreatic insufficient cystic fibrosis; however, the phase was not provided (Boyne J et al. J Med Genet. 2000;37(7):543-7). An in vitro functional study found that this variant did not significantly affect chloride transportation or the maturation of the protein (Vankeerberghen A et al. Hum. Mol. Genet., 1998 Oct;7:1761-9). This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Uncertain significance, criteria provided, single submitterclinical testingGenome-Nilou LabMay 18, 2021- -
not provided Uncertain:4
Uncertain significance, criteria provided, single submitterclinical testingMayo Clinic Laboratories, Mayo ClinicMar 06, 2020- -
Uncertain significance, criteria provided, single submitterclinical testingQuest Diagnostics Nichols Institute San Juan CapistranoFeb 17, 2021- -
Uncertain significance, criteria provided, single submitterclinical testingRevvity Omics, RevvityJun 06, 2019- -
Uncertain significance, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Sep 06, 2018- -
not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpNov 03, 2022Variant summary: CFTR c.2079T>G (p.Phe693Leu) results in a non-conservative amino acid change located in the regulator domain (IPR025837) of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 7.9e-05 in 253336 control chromosomes (gnomAD and Monaghan_2004), predominantly at a frequency of 0.0009 within the African or African-American subpopulation in the gnomAD database, including 1 homozygote. This frequency is not significantly higher than expected for a pathogenic variant in CFTR causing Non-Classic Cystic Fibrosis (7.9e-05 vs 0.013), allowing no conclusion about variant significance. c.2079T>G has been reported in the literature in compound heterozygosity with the 5T variant in an individual affected with Non-Classic Cystic Fibrosis and with p.F508del in a compound heterozygous individual with transient hypertrypsinaemia (e.g. Groman_2002, Boyne_2000). It has also been reported as an uninformative genotype (zygosity/second allele not specified) in an individual affected with Cystic Fibrosis, in the heterozygous state in two individuals with CF-like disease who also harbored variants in the SCNN1G and/or SCNN1B genes as well as in a healthy individual in compound heterozygosity with a pathogenic variant (e.g. Vankeerberghen_1998, Schrijver_2005b, Mutesa_2009). In addition, another variant (c.2077T>C) which leads to the same amino acid change as c.2079T>G, has been reported in a CF patient with an alternative cause for the disease phenotype (e.g. Ferec_1995). These reports do not allow any strong conclusions to be made regarding an association between c.2079T>G and disease. In a functional study, the variant did not significantly affect chloride transport ability in comparison to WT, suggesting it has little to no impact on protein function (Vankeerberghen_1998). Eight submitters have provided clinical-significance assessments for this variant to ClinVar after 2014. The majority classified the variant as VUS (n=7) and one classified it as likely benign. Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -
CFTR-related disorder Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingPreventionGenetics, part of Exact SciencesNov 21, 2022The CFTR c.2079T>G variant is predicted to result in the amino acid substitution p.Phe693Leu. This variant has been reported with a minor allele frequency as high as 0.12% in African populations including one homozygous individual (http://gnomad.broadinstitute.org/variant/7-117232300-T-G), and has been reported as likely benign and a variant of uncertain significance in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/194336/). The c.2079T>G variant has been reported in a CFTR database with the patient presenting with severe asthma (http://www.genet.sickkids.on.ca/MutationDetailPage.external?sp=1209). A different nucleotide substitution, c.2077T>C, resulting in the same amino acid change (p.Phe693Leu) has been reported in a patient with pancreatic insufficiency (http://www.genet.sickkids.on.ca/MutationDetailPage.external?sp=343). This variant has been reported individuals with cystic fibrosis (Groman et al. 2002. PubMed ID: 12167682; Mutesa et al. 2008. PubMed ID: 19017867), pancreatic insufficient cystic fibrosis (Boyne et al. 2000. PubMed ID: 10970190), and healthy individuals (Vankeerberghen et al. 1998. PubMed ID: 9736778). Functional studies have shown that the p.Phe693Leu variant did not significantly affect chloride transport when compared to wild-type CFTR channels (Vankeerberghen et al. 1998. PubMed ID: 9736778). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.49
BayesDel_addAF
Benign
-0.084
T
BayesDel_noAF
Uncertain
0.080
CADD
Benign
15
DANN
Benign
0.91
DEOGEN2
Uncertain
0.51
D;.;T;.
Eigen
Benign
-0.42
Eigen_PC
Benign
-0.35
FATHMM_MKL
Uncertain
0.85
D
LIST_S2
Benign
0.69
T;T;T;T
M_CAP
Uncertain
0.17
D
MetaRNN
Benign
0.092
T;T;T;T
MetaSVM
Uncertain
0.021
D
MutationAssessor
Uncertain
2.0
M;.;.;.
MutationTaster
Benign
0.90
D;N
PrimateAI
Uncertain
0.54
T
PROVEAN
Benign
-0.72
N;.;N;.
REVEL
Uncertain
0.59
Sift
Benign
0.20
T;.;T;.
Sift4G
Benign
0.12
T;.;T;.
Polyphen
0.0
B;.;.;.
Vest4
0.69
MutPred
0.64
Loss of methylation at K688 (P = 0.0951);.;.;.;
MVP
0.98
MPC
0.0038
ClinPred
0.012
T
GERP RS
1.5
Varity_R
0.084
gMVP
0.43

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.

Other links and lift over

dbSNP: rs145540754; hg19: chr7-117232300; API