chr7-117536603-GA-G

Variant names:

• chr7-117536603-GA-G
• rs121908772
• NM_000492.4:c.803delA

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.803delA​(p.Asn268IlefsTer17) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000373 in 1,609,626 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: CFTR NM_000492.4 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:11
• Conservation: PhyloP100: 8.79

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: 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
• PP5: Variant 7-117536603-GA-G is Pathogenic according to our data. Variant chr7-117536603-GA-G is described in ClinVar as [Pathogenic]. Clinvar id is 48700.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr7-117536603-GA-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CFTR	NM_000492.4	c.803delA	p.Asn268IlefsTer17	frameshift_variant	Exon 7 of 27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.803delA	p.Asn268IlefsTer17	frameshift_variant	Exon 7 of 27	1	NM_000492.4	ENSP00000003084.6

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152140 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000203 AC: 5 AN: 246354 Hom.: 0 AF XY: 0.0000225 AC XY: 3 AN XY: 133218

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000146

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS 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: 0.00000343 AC: 5 AN: 1457486 Hom.: 0 Cov.: 31 AF XY: 0.00000414 AC XY: 3 AN XY: 724952

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000112

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152140 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74316

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000655

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:11

Revision: reviewed by expert panel

Submissions by phenotype

Cystic fibrosis Pathogenic:6

Sep 27, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is also known as 935delA. This premature translational stop signal has been observed in individual(s) with cystic fibrosis (PMID: 10798368, 18456578, 22975760). This variant is present in population databases (rs121908772, gnomAD 0.01%). This sequence change creates a premature translational stop signal (p.Asn268Ilefs*17) 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). For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 48700). -

Oct 14, 2019

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.803delA (p.Asn268IlefsX17) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 2e-05 in 246354 control chromosomes. c.803delA has been reported in the literature in individuals affected with Cystic Fibrosis (example, Orozco_2000, Wong_2001, Wang_2000, Schrijver_2008) as a relatively common CF causing allele identified in US Hispanics (Schrijver_2008). These data indicate that the variant is likely to be associated with disease. No experimental evidence demonstrating an impact on protein function were ascertained or evaluated in the scope of this classification. One clinical diagnostic laboratory and the CFTR2 database have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Both submitters classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Mar 17, 2017

CFTR2

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: research

- -

Sep 06, 2022

Johns Hopkins Genomics, Johns Hopkins University

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Disease-causing CFTR variant. See www.CFTR2.org for phenotype information. -

Sep 24, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.803delA pathogenic mutation, located in coding exon 7 of the CFTR gene, results from a deletion of one nucleotide at nucleotide position 803, causing a translational frameshift with a predicted alternate stop codon (p.N268Ifs*17). This alteration was described in two individuals with a second CFTR alteration, failure to thrive, meconium ileus, elevated sweat chloride levels, and pancreatic insufficiency (Wang J et al. Mol. Genet. Metab., 2000 Aug;70:316-21). In addition to the clinical data presented in the literature, 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. -

Dec 04, 2019

Myriad Genetics, Inc.

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

NM_000492.3(CFTR):c.803delA(N268Ifs*17, aka 935delA) is classified as pathogenic in the context of cystic fibrosis. Sources cited for classification include the following: PMID 10993719 and 21416780. Classification of NM_000492.3(CFTR):c.803delA(N268Ifs*17, aka 935delA) is based on the following criteria: The variant causes a premature termination codon that is expected to be targeted by nonsense-mediated mRNA decay and is reported in individuals with the relevant phenotype. Please note: this variant was assessed in the context of healthy population screening. -

not provided Pathogenic:2

Mar 20, 2023

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 20, 2013

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

CFTR-related disorder Pathogenic:1

Mar 17, 2017

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

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

Apr 04, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1

Mar 29, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs121908772; hg19: chr7-117176657;