NM_000492.4:c.418C>G

Variant names:

• chr7-117531043-C-G
• NM_000492.4:c.418C>G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000492.4(CFTR):​c.418C>G​(p.Pro140Ala) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 5.76

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 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
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.948

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CFTR	NM_000492.4	c.418C>G	p.Pro140Ala	missense_variant	Exon 4 of 27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.418C>G	p.Pro140Ala	missense_variant	Exon 4 of 27	1	NM_000492.4	ENSP00000003084.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cystic fibrosis Uncertain:2

Apr 08, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.P140A variant (also known as c.418C>G), located in coding exon 4 of the CFTR gene, results from a C to G substitution at nucleotide position 418. The proline at codon 140 is replaced by alanine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Mar 07, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals affected with CFTR-related conditions. This sequence change replaces proline, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 140 of the CFTR protein (p.Pro140Ala). This variant is not present in population databases (gnomAD no frequency). 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. -

not specified Uncertain:1

Jan 08, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

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	0.26
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.65	D;.;.;T;.
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.97	D;D;D;D;D
M_CAP	Pathogenic	0.66	D
MetaRNN	Pathogenic	0.95	D;D;D;D;D
MetaSVM	Pathogenic	0.79	D
MutationAssessor	Uncertain	2.4	M;.;.;.;M
PrimateAI	Uncertain	0.61	T
PROVEAN	Benign	-2.3	N;.;.;N;.
REVEL	Pathogenic	0.82
Sift	Uncertain	0.027	D;.;.;D;.
Sift4G	Pathogenic	0.0	D;.;.;D;.
Polyphen		1.0	D;.;.;.;.
Vest4		0.78
MutPred		0.79		Loss of catalytic residue at L138 (P = 0.3754);Loss of catalytic residue at L138 (P = 0.3754);Loss of catalytic residue at L138 (P = 0.3754);Loss of catalytic residue at L138 (P = 0.3754);Loss of catalytic residue at L138 (P = 0.3754);
MVP		1.0
MPC		0.0048
ClinPred		0.94	D
GERP RS		5.7
Varity_R		0.51
gMVP		0.91

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr7-117171097;