7-117504278-G-T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000492.4(CFTR):​c.79G>T​(p.Gly27*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000206 in 1,458,524 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

CFTR
NM_000492.4 stop_gained

Scores

5
1

Clinical Significance

Pathogenic reviewed by expert panel P:8

Conservation

PhyloP100: 7.71

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: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 1224 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 7-117504278-G-T is Pathogenic according to our data. Variant chr7-117504278-G-T is described in ClinVar as Pathogenic. ClinVar VariationId is 54061.Status of the report is reviewed_by_expert_panel, 3 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000492.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CFTR
NM_000492.4
MANE Select
c.79G>Tp.Gly27*
stop_gained
Exon 2 of 27NP_000483.3

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CFTR
ENST00000003084.11
TSL:1 MANE Select
c.79G>Tp.Gly27*
stop_gained
Exon 2 of 27ENSP00000003084.6
CFTR
ENST00000546407.1
TSL:1
n.192G>T
non_coding_transcript_exon
Exon 3 of 3
CFTR
ENST00000699605.1
c.-165G>T
5_prime_UTR_premature_start_codon_gain
Exon 3 of 27ENSP00000514473.1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000399
AC:
1
AN:
250926
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000883
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000206
AC:
3
AN:
1458524
Hom.:
0
Cov.:
29
AF XY:
0.00
AC XY:
0
AN XY:
725830
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33402
American (AMR)
AF:
0.00
AC:
0
AN:
44710
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26094
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39614
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86184
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53412
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5752
European-Non Finnish (NFE)
AF:
0.00000270
AC:
3
AN:
1109088
Other (OTH)
AF:
0.00
AC:
0
AN:
60268
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00250614), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.325
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.00000473
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:8
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

Cystic fibrosis Pathogenic:6
Jun 22, 2016
Counsyl
Significance:Pathogenic
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.

Jul 07, 2022
Ambry Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.G27* pathogenic mutation (also known as c.79G>T), located in coding exon 2 of the CFTR gene, results from a G to T substitution at nucleotide position 79. This changes the amino acid from a glycine to a stop codon within coding exon 2. This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation.

Sep 10, 2020
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in CFTR are known to be pathogenic (PMID: 1695717, 7691345, 9725922). This variant has been observed in individual(s) with cystic fibrosis (PMID: 1284531). In at least one individual the data is consistent with the variant being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 54061). This variant is present in population databases (rs397508796, ExAC 0.002%). This sequence change creates a premature translational stop signal (p.Gly27*) in the CFTR gene. It is expected to result in an absent or disrupted protein product.

Jun 05, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: CFTR c.79G>T (p.Gly27X) results in a premature termination codon, predicted to cause absence of the protein due to nonsense mediated decay, which is a commonly known mechanism for disease. The variant allele was found at a frequency of 4e-06 in 250926 control chromosomes (gnomAD). c.79G>T has been reported in the literature in individuals affected with Cystic Fibrosis (e.g. Raraigh_2022). The following publication has been ascertained in the context of this evaluation (PMID: 34782259). Six submitters, including an expert panel, have provided clinical-significance assessments for this variant to ClinVar after 2014, and classified it as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic.

Jan 29, 2018
CFTR-France
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:curation

Mar 17, 2017
CFTR2
Significance:Pathogenic
Review Status:reviewed by expert panel
Collection Method:research

CFTR-related disorder Pathogenic:1
Mar 17, 2017
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1
Oct 04, 2023
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.63
CADD
Pathogenic
38
DANN
Uncertain
0.99
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
0.93
FATHMM_MKL
Pathogenic
0.98
D
PhyloP100
7.7
Vest4
0.93
GERP RS
4.8
Mutation Taster
=0/200
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs397508796; hg19: chr7-117144332; API