rs372227120

Positions:

• chr7-117665565-G-A
• chr7-117665565-G-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000492.4(CFTR):​c.4242+1G>A variant causes a splice donor change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000696 in 1,437,216 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: 33)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
• Consequence: CFTR NM_000492.4 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic reviewed by expert panel P:8 O:1
• Conservation: PhyloP100: 9.15

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 Pathogenic. Variant got 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-117665565-G-A is Pathogenic according to our data. Variant chr7-117665565-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 53929.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr7-117665565-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CFTR	NM_000492.4	c.4242+1G>A		splice_donor_variant		ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.4242+1G>A		splice_donor_variant		1	NM_000492.4	ENSP00000003084	P2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.96e-7 AC: 1 AN: 1437216 Hom.: 0 Cov.: 26 AF XY: 0.00000140 AC XY: 1 AN XY: 716478

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000117

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Cystic fibrosis Pathogenic:6 Other:1

not provided, no classification provided	literature only	ClinVar Staff, National Center for Biotechnology Information (NCBI)	-	- -
Pathogenic, criteria provided, single submitter	curation	Institute of Human Genetics, University of Leipzig Medical Center	Sep 05, 2022	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: PVS1_STR, PS1_SUP, PM2_SUP, PM3_STR, PP4 -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	May 27, 2022	For these reasons, this variant has been classified as Pathogenic. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 53929). This variant is also known as c.4374 +1G>A. Disruption of this splice site has been observed in individuals with cystic fibrosis (PMID: 7682196, 15074370, 29504914). This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 26 of the CFTR gene. While this variant is not anticipated to result in nonsense mediated decay, it likely alters RNA splicing and results in a disrupted protein product. -
Pathogenic, reviewed by expert panel	research	CFTR2	Mar 17, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Sep 01, 2021	Variant summary: CFTR c.4242+1G>A is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes the canonical 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 250642 control chromosomes. c.4242+1G>A has been reported in the literature in individuals affected with Cystic Fibrosis (example, Fanen_1992, Kay_2015, Ivanov_2018, Petrova_2019). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One clinical diagnostic laboratory and two databases (CFTR-France and CFTR2) have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All submitters classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	curation	CFTR-France	Jan 29, 2018	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	May 26, 2017	- -

CFTR-related disorder Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Natera, Inc.

Mar 17, 2017

- -

Cystic fibrosis;C0238339:Hereditary pancreatitis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation;C2749757:Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 29, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	30
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.97	D
MutationTaster	Benign	1.0	D;D
GERP RS		5.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.99		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs372227120; hg19: chr7-117305619;