chr7-117642487-C-CT

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_000492.4(CFTR):​c.3773dupT​(p.Leu1258PhefsTer7) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,504 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Synonymous variant affecting the same amino acid position (i.e. L1258L) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

CFTR
NM_000492.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic reviewed by expert panel P:18

Conservation

PhyloP100: -0.238

Publications

16 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 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 7-117642487-C-CT is Pathogenic according to our data. Variant chr7-117642487-C-CT is described in ClinVar as Pathogenic. ClinVar VariationId is 38726.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CFTRNM_000492.4 linkc.3773dupT p.Leu1258PhefsTer7 frameshift_variant Exon 23 of 27 ENST00000003084.11 NP_000483.3 P13569-1A0A024R730
CFTR-AS2NR_199597.1 linkn.65+4863dupA intron_variant Intron 1 of 2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CFTRENST00000003084.11 linkc.3773dupT p.Leu1258PhefsTer7 frameshift_variant Exon 23 of 27 1 NM_000492.4 ENSP00000003084.6 P13569-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152110
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000797
AC:
2
AN:
251050
AF XY:
0.0000147
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:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000411
AC:
6
AN:
1461394
Hom.:
0
Cov.:
32
AF XY:
0.00000688
AC XY:
5
AN XY:
727004
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33450
American (AMR)
AF:
0.00
AC:
0
AN:
44690
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26112
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39662
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53394
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5760
European-Non Finnish (NFE)
AF:
0.00000540
AC:
6
AN:
1111698
Other (OTH)
AF:
0.00
AC:
0
AN:
60374
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.508
Heterozygous variant carriers
0
1
2
3
4
5
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
AF:
0.00000657
AC:
1
AN:
152110
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74304
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41424
American (AMR)
AF:
0.00
AC:
0
AN:
15246
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000263
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:18
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

Cystic fibrosis Pathogenic:7
Jan 29, 2018
CFTR-France
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:curation

- -

Nov 11, 2020
Johns Hopkins Genomics, Johns Hopkins University
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Disease-causing CFTR variant. See www.CFTR2.org for phenotype information. -

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

- -

Dec 09, 2019
Myriad Genetics, Inc.
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

NM_000492.3(CFTR):c.3773dupT(L1258Ffs*7, aka 3905insT) is classified as pathogenic in the context of cystic fibrosis and is associated with classic disease. Sources cited for classification include the following: PMID 19724303 and 23974870. Classification of NM_000492.3(CFTR):c.3773dupT(L1258Ffs*7, aka 3905insT) is based on the following criteria: The variant causes a premature termination codon that is expected to be targeted by nonsense-mediated mRNA decay and is reported in individuals with the relevant phenotype. Please note: this variant was assessed in the context of healthy population screening. -

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

This sequence change creates a premature translational stop signal (p.Leu1258Phefs*7) in the CFTR gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CFTR are known to be pathogenic (PMID: 1695717, 7691345, 9725922). This variant is present in population databases (rs796566397, gnomAD 0.002%). This premature translational stop signal has been observed in individuals with cystic fibrosis (PMID: 19724303, 21520337, 23974870). This variant is also known as 3905insT. ClinVar contains an entry for this variant (Variation ID: 38726). For these reasons, this variant has been classified as Pathogenic. -

May 30, 2023
Ambry Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.3773dupT pathogenic mutation (also known as c.3773_3774insT and 3905insT), located in coding exon 23 of the CFTR gene, results from a duplication of T at nucleotide position 3773, causing a translational frameshift with a predicted alternate stop codon (p.L1258Ffs*7). This mutation was described in 30 compound heterozygous individuals with cystic fibrosis characterized by elevated sweat chloride levels, failure to thrive, pancreatic insufficiency, and progressively decreasing lung function (Schibler A et al. Eur. Respir. J., 2001 Jun;17:1181-6). Immunocytochemical studies demonstrated that this alteration significantly reduces the amount of mature CFTR protein found in the apical membranes of nasal epithelia (Sanz J et al. Eur. J. Hum. Genet., 2010 Feb;18:212-7). This mutation is associated with elevated sweat chloride levels and pancreatic insufficiency (Sosnay PR et al. Nat. Genet., 2013 Oct;45:1160-7). In addition to the clinical data presented in the literature, 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 05, 2022
Institute of Human Genetics, University of Leipzig Medical Center
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:curation

This variant was identified in 3 unrelated patients 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: PVS1_STR, PS3_MOD, PM2_SUP, PM3_STR, PP4 -

not provided Pathogenic:7
Jul 08, 2022
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The CFTR c.3773dupT; p.Leu1258PhefsTer7 (rs387906370) variant, also known as 3905insT, is reported in multiple individuals diagnosed with cystic fibrosis (Dork 1994, Gallati 2009, Hirtz 2004, Sosnay 2013) and is generally associated with pancreatic insufficiency (Ooi 2012, Sosnay 2013, CFTR2 database). Functional characterization of the variant indicates that the transcript is insensitive to nonsense-medicated decay or nonsense-associated alternative splicing (Sanz 2010). The variant protein fails to mature and localize to the cell surface (Sanz 2010), resulting in severe reduction in chloride transport activity (Hirtz 2004). This variant is also reported in the ClinVar database (Variation ID: 38726). It is only observed on three alleles in the Genome Aggregation Database, indicating it is not a common polymorphism. The variant introduces a frameshift, and functional studies indicate it results in a truncated, inactive protein. Based on available information, this variant is considered to be pathogenic. References: CFTR2 database: http://cftr2.org/ Dork T et al. Detection of more than 50 different CFTR mutations in a large group of German cystic fibrosis patients. Hum Genet. 1994; 94(5):533-42. Gallati S et al. Cystic fibrosis transmembrane conductance regulator mutations in azoospermic and oligospermic men and their partners. Reprod Biomed Online. 2009; 19(5):685-94. Hirtz S et al. CFTR Cl- channel function in native human colon correlates with the genotype and phenotype in cystic fibrosis. Gastroenterology. 2004; 2004 Oct;127(4):1085-95. Ooi C. et al. Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations in pancreatitis. J Cyst Fibros. 2012; 11(5):355-62. Sanz J et al. The CFTR frameshift mutation 3905insT and its effect at transcript and protein level. Eur J Hum Genet. 2010; 18(2):212-7. Sosnay PR et al. Defining the disease liability of variants in the cystic fibrosis transmembrane conductance regulator gene. Nat Genet. 2013; 45(10):1160-7. -

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

CFTR: PVS1, PM2, PM3 -

Jun 01, 2021
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The frameshift variant causes the premature termination of CFTR protein synthesis. This variant causes cystic fibrosis (CF) when co-occurring with a CF-causing variant in trans and has also been reported in individuals affected with chronic pancreatitis in the published literature (PMID: 7525450 (1994), 23974870 (2013), 21520337 (2011), 19724303 (2010)). Additionally, immunohistochemical staining of the CFTR protein in patient nasal epithelial cells revealed that this variant significantly impairs expression (PMID: 19724303 (2010)). The frequency of this variant in the general population is consistent with pathogenicity. Therefore, the variant is classified as pathogenic. -

Dec 20, 2021
Mayo Clinic Laboratories, Mayo Clinic
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Mar 17, 2022
AiLife Diagnostics, AiLife Diagnostics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

CFTR-related disorder Pathogenic:2
Mar 17, 2017
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Mar 22, 2024
PreventionGenetics, part of Exact Sciences
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

The CFTR c.3773dupT variant is predicted to result in a frameshift and premature protein termination (p.Leu1258Phefs*7). This variant, sometimes described as 3905insT using legacy nomenclature, has been reported in the compound heterozygous or homozygous state in many individuals with cystic fibrosis (Liechti-Gallati et al. 1992. PubMed ID: 1380689; Hirtz S et al 2004. PubMed ID: 15480987; Hergersberg M et al 1997. PubMed ID: 9254853; Sanz J et al 2009. PubMed ID: 19724303; CFTR2.org), as well as CFTR-related disorders including pancreatic insufficiency (Ooi and Durie. 2012. PubMed ID: 22658665) and congenital bilateral absence of the vas deferens (Steiner et al. 2011. PubMed ID: 21520337). This variant was also reported to be the second most common pathogenic CFTR variant in the Swiss population and is associated with a severe phenotype when in the presence of p.Phe508del (Hergersberg M et al 1997. PubMed ID: 9254853). Functional studies indicate this variant does not result in nonsense-mediated decay or nonsense-associated alternative splicing, but does reduce the amount of CFTR protein at the apical membrane (Sanz J et al 2009. PubMed ID: 19724303). This variant is reported in 0.0023% of alleles in individuals of European (Non-Finnish) descent in gnomAD. Frameshift variants in CFTR are expected to be pathogenic. This variant is interpreted as pathogenic. -

Cystic fibrosis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation Pathogenic:1
-
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1
Mar 27, 2024
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
-0.24
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: rs121908789; hg19: chr7-117282541; COSMIC: COSV50099599; API