NM_000492.4:c.79G>T

Variant names:

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

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)

CFTR links:

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	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CFTR	NM_000492.4	MANE Select	c.79G>T	p.Gly27*	stop_gained	Exon 2 of 27	NP_000483.3

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
CFTR	ENST00000003084.11	TSL:1 MANE Select	c.79G>T	p.Gly27*	stop_gained	Exon 2 of 27	ENSP00000003084.6
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 27	ENSP00000514473.1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000399

AC:

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:

AN:

1458524

Hom.:

Cov.:

AF XY:

0.00

AC XY:

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:

AN:

33402

American (AMR)

AF:

0.00

AC:

AN:

44710

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26094

East Asian (EAS)

AF:

0.00

AC:

AN:

39614

South Asian (SAS)

AF:

0.00

AC:

AN:

86184

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53412

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5752

European-Non Finnish (NFE)

AF:

0.00000270

AC:

AN:

1109088

Other (OTH)

AF:

0.00

AC:

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

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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.:

Alfa

AF:

0.00000473

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

Cystic fibrosis

Pathogenic:6

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.

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.

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.

Jan 29, 2018

CFTR-France

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:curation

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.

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

BayesDel_noAF

Pathogenic

0.63

CADD

Pathogenic

(source)

DANN

Uncertain

0.99

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.93

FATHMM_MKL

Pathogenic

0.98

PhyloP100

7.7

Vest4

0.93

GERP RS

4.8

Mutation Taster

=0/200

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over