rs397508598

Variant names:

• chr7-117642439-T-G
• rs397508598
• NM_000492.4:c.3719T>G

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1 PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_000492.4(CFTR):​c.3719T>G​(p.Val1240Gly) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,124 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V1240L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CFTR NM_000492.4 missense, splice_region
• Scores: Splicing: ADA: 0.3127
• Clinical Significance: Pathogenic reviewed by expert panel P:5 O:1
• Conservation: PhyloP100: 7.36
• Publications: 7 publications found

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)

ENSG00000083622 (HGNC:40145):

ACMG classification

Our verdict: Pathogenic. The variant received 17 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 11 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, 0.987
• PP5: Variant 7-117642439-T-G is Pathogenic according to our data. Variant chr7-117642439-T-G is described in ClinVar as [Pathogenic]. Clinvar id is 53795.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CFTR	NM_000492.4	c.3719T>G	p.Val1240Gly	missense_variant, splice_region_variant	Exon 23 of 27	ENST00000003084.11	NP_000483.3
CFTR-AS2	NR_199597.1	n.65+4912A>C		intron_variant	Intron 1 of 2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.3719T>G	p.Val1240Gly	missense_variant, splice_region_variant	Exon 23 of 27	1	NM_000492.4	ENSP00000003084.6

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 250942 AF XY: 0.00000737

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: 0.00000882

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461124 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 726898

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33440

American (AMR) AF: 0.00 AC: 0 AN: 44690

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26106

East Asian (EAS) AF: 0.00 AC: 0 AN: 39660

South Asian (SAS) AF: 0.00 AC: 0 AN: 86244

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53398

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111462

Other (OTH) AF: 0.00 AC: 0 AN: 60362

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000508 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Cystic fibrosis Pathogenic:5 Other:1

Mar 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces valine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 1240 of the CFTR protein (p.Val1240Gly). This variant is present in population databases (rs397508598, gnomAD 0.0009%). This missense change has been observed in individuals with clinical features of CFTR-related conditions (PMID: 20059485, 22892530, 23974870, 30888834; Invitae). ClinVar contains an entry for this variant (Variation ID: 53795). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -

Sep 16, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

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ClinVar Staff, National Center for Biotechnology Information (NCBI)

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Aug 16, 2024

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: CFTR c.3719T>G (p.Val1240Gly) results in a non-conservative amino acid change located in the ABC transporter-like, ATP-binding domain 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 4e-06 in 250942 control chromosomes (gnomAD). c.3719T>G has been reported in the literature in multiple individuals affected with Cystic Fibrosis and related disorders (e.g. Sobczynska-Tomaszewska_2013, Lucarelli_2015, McCague_2019). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect resulted in approximately 34% of normal chloride channel conductance relative to wild type (e.g., Bihler_2024). The variant is reported to be FDA-approved for treatment with ivacaftor + tezacaftor + elexacaftor and ivacaftor + tezacaftor (Raraigh_2022). The following publications have been ascertained in the context of this evaluation (PMID: 22892530, 18292811, 25910067, 30888834, 33085659, 35527187, 38388235). ClinVar contains an entry for this variant (Variation ID: 53795). Based on the evidence outlined above, the variant was classified as pathogenic. -

Sep 05, 2022

Institute of Human Genetics, University of Leipzig Medical Center

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

This variant was identified in 1 patient 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: PM2_SUP, PM3_STR, PP3 -

Aug 31, 2018

CFTR2

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: research

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.56
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.50
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D;D;.
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.96	D;D;D
M_CAP	Pathogenic	0.62	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.2	M;.;.
PhyloP100		7.4
PrimateAI	Uncertain	0.57	T
PROVEAN	Pathogenic	-5.8	D;D;.
REVEL	Pathogenic	0.97
Sift	Uncertain	0.0010	D;D;.
Sift4G	Uncertain	0.0040	D;D;.
Polyphen		0.99	D;.;.
Vest4		0.75
MutPred		0.94		Loss of stability (P = 0.0049);.;.;
MVP		1.0
MPC		0.013
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.99
gMVP		0.97
Mutation Taster		=5/95	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.31
dbscSNV1_RF	Benign	0.52
SpliceAI score (max)		0.14		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs397508598; hg19: chr7-117282493;