rs397508735

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_ModeratePM2PP5_Moderate

The NM_000492.4(CFTR):c.490-2A>G variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000741 in 1,349,034 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 predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 7.4e-7 ( 0 hom. )

Consequence

CFTR
NM_000492.4 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic criteria provided, single submitter P:2O:1

Conservation

PhyloP100: 8.47

Publications

1 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)

CFTR links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.020256583 fraction of the gene. Cryptic splice site detected, with MaxEntScore 6.8, offset of 9, new splice context is: ttttcttttggactttaaAGctg. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 7-117534274-A-G is Pathogenic according to our data. Variant chr7-117534274-A-G is described in ClinVar as Pathogenic. ClinVar VariationId is 53975.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CFTR	NM_000492.4 link	c.490-2A>G		splice_acceptor_variant, intron_variant	Intron 4 of 26	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11 link	c.490-2A>G		splice_acceptor_variant, intron_variant	Intron 4 of 26	1	NM_000492.4	ENSP00000003084.6

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000401

AC:

AN:

249286

AF XY:

0.00000741

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000291

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

7.41e-7

AC:

AN:

1349034

Hom.:

Cov.:

AF XY:

0.00000148

AC XY:

AN XY:

677326

show subpopulations

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

African (AFR)

AF:

0.00

AC:

AN:

31220

American (AMR)

AF:

0.0000225

AC:

AN:

44436

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25330

East Asian (EAS)

AF:

0.00

AC:

AN:

39060

South Asian (SAS)

AF:

0.00

AC:

AN:

83356

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52346

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5516

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1011192

Other (OTH)

AF:

0.00

AC:

AN:

56578

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2Other:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Cystic fibrosis

Pathogenic:1Other:1

ClinVar Staff, National Center for Biotechnology Information (NCBI)

Significance:not provided

Review Status:no classification provided

Collection Method:literature only

Mar 28, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change affects an acceptor splice site in intron 4 of the CFTR gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in CFTR are known to be pathogenic (PMID: 1695717, 7691345, 9725922). This variant is present in population databases (rs397508735, gnomAD 0.003%). Disruption of this splice site has been observed in individuals with cystic fibrosis (PMID: 16423550, 23857699). This variant is also known as 622-2A>G. ClinVar contains an entry for this variant (Variation ID: 53975). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic.

CFTR-related disorder

Pathogenic:1

Mar 17, 2017

Natera, Inc.

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.57

BayesDel_noAF

Pathogenic

0.36

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.0

.;.;.;.

Eigen

Pathogenic

1.2

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Benign

0.0

.;.;.;.

MetaRNN

Benign

0.0

.;.;.;.

MutationAssessor

Benign

0.0

.;.;.;.

PhyloP100

8.5

PROVEAN

Benign

0.0

.;.;.;.

REVEL

Benign

0.0

Sift

Pathogenic

0.0

.;.;.;.

Sift4G

Pathogenic

0.0

.;.;.;.

Vest4

0.0

GERP RS

5.5

Mutation Taster

=0/100

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.93

SpliceAI score (max)

0.99

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.98

Position offset: 11

DS_AL_spliceai

0.99

Position offset: 2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over