chr7-117535277-C-G

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1PM2PP2PP3_Strong

The NM_000492.4(CFTR):​c.609C>G​(p.Ile203Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,852 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 Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. I203I) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

CFTR
NM_000492.4 missense

Scores

6
8
5

Clinical Significance

Uncertain significance criteria provided, single submitter U:1O:1

Conservation

PhyloP100: 0.0380

Publications

7 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: Likely_pathogenic. The variant received 9 ACMG points.

PM1
In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 25 uncertain in NM_000492.4
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 197 curated pathogenic missense variants (we use a threshold of 10). The gene has 46 curated benign missense variants. Gene score misZ: -3.1397 (below the threshold of 3.09). Trascript score misZ: -1.0868 (below the threshold of 3.09). GenCC associations: The gene is linked to hereditary chronic pancreatitis, cystic fibrosis, congenital bilateral absence of vas deferens.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.952

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CFTRNM_000492.4 linkc.609C>G p.Ile203Met missense_variant Exon 6 of 27 ENST00000003084.11 NP_000483.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CFTRENST00000003084.11 linkc.609C>G p.Ile203Met missense_variant Exon 6 of 27 1 NM_000492.4 ENSP00000003084.6

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461852
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727220
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111986
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.00
Hom.:
0

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1Other:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Cystic fibrosis Uncertain:1Other:1
-
ClinVar Staff, National Center for Biotechnology Information (NCBI)
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

- -

Aug 04, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 203 of the CFTR protein (p.Ile203Met). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with CFTR-related disease (PMID: 20059485). ClinVar contains an entry for this variant (Variation ID: 54025). 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 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.29
BayesDel_addAF
Pathogenic
0.35
D
BayesDel_noAF
Pathogenic
0.27
CADD
Benign
13
DANN
Uncertain
0.98
DEOGEN2
Uncertain
0.53
D;.;.;T;.
Eigen
Benign
-0.53
Eigen_PC
Benign
-0.73
FATHMM_MKL
Uncertain
0.83
D
LIST_S2
Uncertain
0.96
D;D;D;D;D
M_CAP
Pathogenic
0.66
D
MetaRNN
Pathogenic
0.95
D;D;D;D;D
MetaSVM
Uncertain
0.47
D
MutationAssessor
Uncertain
2.6
M;.;.;.;M
PhyloP100
0.038
PrimateAI
Uncertain
0.67
T
PROVEAN
Benign
-0.30
N;.;.;N;.
REVEL
Pathogenic
0.65
Sift
Uncertain
0.025
D;.;.;D;.
Sift4G
Pathogenic
0.0
D;.;.;D;.
Polyphen
1.0
D;.;.;.;.
Vest4
0.96
MutPred
0.86
Gain of catalytic residue at I203 (P = 0.3983);Gain of catalytic residue at I203 (P = 0.3983);Gain of catalytic residue at I203 (P = 0.3983);.;Gain of catalytic residue at I203 (P = 0.3983);
MVP
0.97
MPC
0.015
ClinPred
0.80
D
GERP RS
-4.7
Varity_R
0.64
gMVP
0.84
Mutation Taster
=18/82
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.040
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: rs1800081; hg19: chr7-117175331; API