7-117611735-G-T

Position:

• chr7-117611735-G-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000492.4(CFTR):​c.3294G>T​(p.Trp1098Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. W1098?) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:5
• Conservation: PhyloP100: 9.89

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]

ENSG00000083622 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PM1: In a helix (size 50) in uniprot entity CFTR_HUMAN there are 11 pathogenic changes around while only 0 benign (100%) in NM_000492.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr7-117611735-G-Y is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 7-117611735-G-T is Pathogenic according to our data. Variant chr7-117611735-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 618905.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CFTR	NM_000492.4	c.3294G>T	p.Trp1098Cys	missense_variant	20/27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.3294G>T	p.Trp1098Cys	missense_variant	20/27	1	NM_000492.4	ENSP00000003084.6

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: reviewed by expert panel

Submissions by phenotype

Cystic fibrosis Pathogenic:4

Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 24, 2021	Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C15"). ClinVar contains an entry for this variant (Variation ID: 618905). This variant is also known as c.3426G>T. This missense change has been observed in individual(s) with cystic fibrosis (PMID: 10798368, 14998948, 16963320, 21416780). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces tryptophan, which is neutral and slightly polar, with cysteine, which is neutral and slightly polar, at codon 1098 of the CFTR protein (p.Trp1098Cys). Experimental studies have shown that this missense change affects CFTR function (PMID: 30046002). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant disrupts the p.Trp1098 amino acid residue in CFTR. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 7537150, 8662892). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Oct 22, 2024	Variant summary: CFTR c.3294G>T (p.Trp1098Cys) results in a non-conservative amino acid change located in the ABC transporter type 1, 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 was absent in 251088 control chromosomes. c.3294G>T has been reported in the literature in individuals affected with Cystic Fibrosis and Congenital Bilateral Absence Of The Vas Deferens (examples: Orozco_2000, Danziger_2004). These data indicate that the variant may be associated with disease. A different variant resulting in the same amino acid consequence has been classified as pathogenic by our lab (c.3294G>C), supporting the pathogenicity of this variant. The most pronounced variant effect results in <10% of normal activity (example: Han_2018). The following publications have been ascertained in the context of this evaluation (PMID: 14998948, 10798368, 21416780, 30046002, 38388235). ClinVar contains an entry for this variant (Variation ID: 618905). Based on the evidence outlined above, the variant was classified as pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Mendelics	Nov 05, 2018	- -
Pathogenic, reviewed by expert panel	research	CFTR2	Aug 31, 2018	- -

Cystic fibrosis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.87
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.45
CADD	Pathogenic	31
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.91	D;.;.;D;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.98
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D
M_CAP	Pathogenic	0.95	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Pathogenic	3.5	M;.;.;.;.
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-10	D;.;.;D;.
REVEL	Pathogenic	0.93
Sift	Pathogenic	0.0	D;.;.;D;.
Sift4G	Pathogenic	0.0	D;.;.;D;.
Polyphen		1.0	D;.;.;.;.
Vest4		0.99
MutPred		0.94		Loss of catalytic residue at L1096 (P = 0.0029);.;.;.;.;
MVP		0.99
MPC		0.012
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.97
gMVP		0.99

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

Other links and lift over

dbSNP: rs397508533; hg19: chr7-117251789;