rs397508216

chr7-117559558-G-A

Variant summary

Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PVS1 PM2 PP3 PP5_Very_Strong

The NM_000492.4(CFTR):c.1487G>A(p.Trp496Ter) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,050 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 Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CFTR NM_000492.4 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:5 O:1
• Conservation: PhyloP100: 9.43

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-AS1 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 19 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 7-117559558-G-A is Pathogenic according to our data. Variant chr7-117559558-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 53265.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr7-117559558-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CFTR	NM_000492.4	c.1487G>A	p.Trp496Ter	stop_gained	11/27	ENST00000003084.11
CFTR-AS1	NR_149084.1	n.221+1175C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CFTR	ENST00000003084.11	c.1487G>A	p.Trp496Ter	stop_gained	11/27	1	NM_000492.4	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460050 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726480

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Cystic fibrosis Pathogenic:4 Other:1

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Aug 12, 2021	This variant is not present in population databases (ExAC no frequency). For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. This variant has been observed in individual(s) with cystic fibrosis (PMID: 15176679, 7531541, 12752573). This variant is also known as c.1619G>A. ClinVar contains an entry for this variant (Variation ID: 53265). This sequence change creates a premature translational stop signal (p.Trp496*) in the CFTR gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CFTR are known to be pathogenic (PMID: 1695717, 7691345, 9725922). -
Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Dec 03, 2022	The p.W496* pathogenic mutation (also known as c.1487G>A), located in coding exon 11 of the CFTR gene, results from a G to A substitution at nucleotide position 1487. This changes the amino acid from a tryptophan to a stop codon within coding exon 11. This alteration has been identified in individuals diagnosed with cystic fibrosis (Kanavakis E et al. Clin Genet, 2003 May;63:400-9; Decaestecker K et al. Eur Respir J, 2004 May;23:679-84). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -
Pathogenic, reviewed by expert panel	research	CFTR2	Mar 17, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Sep 19, 2017	- -
not provided, no classification provided	literature only	ClinVar Staff, National Center for Biotechnology Information (NCBI)	-	- -

CFTR-related disorder Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Natera, Inc.

Mar 17, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.66
Cadd	Pathogenic	51
Dann	Uncertain	1.0
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	A;A
Vest4		0.97
GERP RS		5.5

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.57		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.57		Position offset: -7

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

Publications

LitVar

Other links and lift over

dbSNP: rs397508216; hg19: chr7-117199612; COSMIC: COSV50041920; COSMIC: COSV50041920;