NM_000492.4:c.418C>T

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1PM2BP4

The NM_000492.4(CFTR):c.418C>T(p.Pro140Ser) variant causes a missense change. The variant allele was found at a frequency of 0.000282 in 1,613,736 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 Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00029 ( 0 hom. )

Consequence

CFTR
NM_000492.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:15

Conservation

PhyloP100: 5.76

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM1

In a domain ABC transmembrane type-1 1 (size 284) in uniprot entity CFTR_HUMAN there are 65 pathogenic changes around while only 10 benign (87%) in NM_000492.4

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.41979367).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CFTR	NM_000492.4 link	c.418C>T	p.Pro140Ser	missense_variant	Exon 4 of 27	ENST00000003084.11	NP_000483.3	P13569-1A0A024R730

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11 link	c.418C>T	p.Pro140Ser	missense_variant	Exon 4 of 27	1	NM_000492.4	ENSP00000003084.6		P13569-1

Frequencies

GnomAD3 genomes

AF:

0.000197

AC:

AN:

152104

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000965

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00116

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000279

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000140

AC:

AN:

250704

Hom.:

AF XY:

0.000162

AC XY:

AN XY:

135464

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000381

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000238

Gnomad OTH exome

AF:

0.000164

GnomAD4 exome

AF:

0.000291

AC:

425

AN:

1461514

Hom.:

Cov.:

AF XY:

0.000275

AC XY:

200

AN XY:

727032

show subpopulations

Gnomad4 AFR exome

AF:

0.0000896

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000101

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

0.000346

Gnomad4 OTH exome

AF:

0.000530

GnomAD4 genome

AF:

0.000197

AC:

AN:

152222

Hom.:

Cov.:

AF XY:

0.000188

AC XY:

AN XY:

74426

show subpopulations

Gnomad4 AFR

AF:

0.0000963

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00116

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000279

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000266

Hom.:

Bravo

AF:

0.000181

ExAC

AF:

0.0000659

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.000436

EpiControl

AF:

0.000178

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:15

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cystic fibrosis

Uncertain:5

Oct 05, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline, which is neutral and non-polar, with serine, which is neutral and polar, at codon 140 of the CFTR protein (p.Pro140Ser). This variant is present in population databases (rs145900055, gnomAD 0.03%). This missense change has been observed in individual(s) with clinical features of CFTR-related conditions (PMID: 15354332, 26708955). ClinVar contains an entry for this variant (Variation ID: 53912). 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 not expected to disrupt CFTR protein function. 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. -

Mar 02, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.P140S variant (also known as c.418C>T), located in coding exon 4 of the CFTR gene, results from a C to T substitution at nucleotide position 418. The proline at codon 140 is replaced by serine, an amino acid with similar properties. This variant was identified in an African American individual undergoing carrier screening (Monaghan KG et al. Genet. Med, 2004;6:141-4). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on available evidence to date, the clinical significance of this alteration remains unclear. -

Jul 23, 2022

Johns Hopkins Genomics, Johns Hopkins University

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

CFTR c.418C>T has been identified in multiple individuals with features of cystic fibrosis and has an entry in ClinVar. This variant (rs145900055) has been identified in a large population dataset and the minor allele frequency is neither low enough to consider the variant rare (<0.1%) nor high enough to consider it a population polymorphism (>1%) within the East Asian subpopulation (gnomAD: 6/5186 alleles; 0.1157%, no homozygotes). BayPR, an algorithm that uses population data to assign disease liability to variants, predicts that this variant is unlikely to be CF causing. Of three bioinformatics tools queried, one/two predict that the substitution would be damaging while one predicts that it would be tolerated. The proline residue at this position is evolutionarily conserved across most species assessed. Due to insufficient evidence that this variant is deleterious, we consider the clinical significance of c.418C>T to be uncertain at this time. -

May 09, 2017

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Sep 05, 2021

Genome-Nilou Lab

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Uncertain:3

May 12, 2022

Mayo Clinic Laboratories, Mayo Clinic

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PP3 -

Dec 28, 2022

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The CFTR c.418C>T; p.Pro140Ser variant (rs145900055) is reported in the literature in individuals affected with cystic fibrosis or CFTR-related disorders, though it was not demonstrated to be disease-causing (Luo 2021, Schrijver 2016, SickKids CFTR database). This variant is also reported in ClinVar (Variation ID: 53912). It is found in the general population with an overall allele frequency of 0.02% (43/282098 alleles) in the Genome Aggregation Database. Computational analyses predict that this variant is deleterious (REVEL: 0.817). However, due to limited information, the clinical significance of this variant is uncertain at this time. References: Luo S et al. Mutation analysis of the cystic fibrosis transmembrane conductance regulator gene in Chinese congenital absence of vas deferens patients. Gene. 2021 Jan 10;765:145045. PMID: 32777524. SickKids CFTR database: http://www.genet.sickkids.on.ca/ Schrijver I et al. The Spectrum of CFTR Variants in Nonwhite Cystic Fibrosis Patients: Implications for Molecular Diagnostic Testing. J Mol Diagn. 2016 Jan;18(1):39-50. PMID: 26708955. -

Oct 11, 2017

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified

Uncertain:2

Jun 24, 2024

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.418C>T (p.Pro140Ser) results in a non-conservative amino acid change located in the first transmembrane domain (IPR011527) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00014 in 263036 control chromosomes (gnomAD). This frequency is not higher than the estimated maximum expected for a pathogenic variant in CFTR causing Classic Cystic Fibrosis (0.013), allowing no conclusion about variant significance. c.418C>T has been reported in the literature in individuals affected with Cystic Fibrosis (e.g. Schrijver_2016, Salinas_2023) without strong evidence for or against pathogenicity. It has also been reported in the literature as a variant of uncertain significance (e.g. Monaghan_2004; Audrezet_2008). These reports do not provide unequivocal conclusions about association of the variant with Classic Cystic Fibrosis. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect resulted in approximately (Gt channel conductance) 12% of normal chloride channel conductance relative to wild type (e.g., Bihler_2024). The following publications have been ascertained in the context of this evaluation (PMID: 18687795, 32777524, 15354332, 26708955, 17380060, 36409994, 38388235). ClinVar contains an entry for this variant (Variation ID: 53912). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Jan 10, 2017

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

CFTR-related disorder

Uncertain:2

May 10, 2024

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

The CFTR c.418C>T variant is predicted to result in the amino acid substitution p.Pro140Ser. This variant has been previously reported a patient with disseminated bronchiectasis (Schrijver I et al 2016. PubMed ID: 26708955; http://www.genet.sickkids.on.ca/cftr/MutationDetailPage.external?sp=99). A different missense change at the same position (p.Pro140Leu) has also been reported in a patient with mild bronchitis (http://www.genet.sickkids.on.ca/cftr/MutationDetailPage.external?sp=802). This variant is reported in 0.035% of alleles in individuals of East Asian descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Apr 28, 2017

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Hereditary pancreatitis

Uncertain:1

Apr 14, 2021

Sema4, Sema4

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: curation

- -

Cystic fibrosis;C0238339:Hereditary pancreatitis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation;C2749757:Bronchiectasis with or without elevated sweat chloride 1

Uncertain:1

Apr 11, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Bronchiectasis with or without elevated sweat chloride 1

Uncertain:1

Dec 30, 2023

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.31

BayesDel_addAF

Pathogenic

0.19

BayesDel_noAF

Pathogenic

0.35

CADD

Uncertain

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.63

D;.;.;T;.

Eigen

Pathogenic

0.75

Eigen_PC

Pathogenic

0.73

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.94

D;D;D;D;D

M_CAP

Pathogenic

0.70

MetaRNN

Benign

0.42

T;T;T;T;T

MetaSVM

Uncertain

0.72

MutationAssessor

Benign

1.9

L;.;.;.;L

PrimateAI

Uncertain

0.61

PROVEAN

Benign

-1.8

N;.;.;N;.

REVEL

Pathogenic

0.82

Sift

Uncertain

0.017

D;.;.;D;.

Sift4G

Pathogenic

0.0

D;.;.;D;.

Polyphen

1.0

D;.;.;.;.

Vest4

0.70

MVP

1.0

MPC

0.0047

ClinPred

0.11

GERP RS

5.7

Varity_R

0.50

gMVP

0.94

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over