chr7-117509132-T-G

Variant names:

• chr7-117509132-T-G
• rs397508412
• NM_000492.4:c.263T>G

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.263T>G​(p.Leu88*) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000657 in 152,244 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: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: CFTR NM_000492.4 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:9
• Conservation: PhyloP100: 6.21

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 7-117509132-T-G is Pathogenic according to our data. Variant chr7-117509132-T-G is described in ClinVar as [Pathogenic]. Clinvar id is 53534.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr7-117509132-T-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CFTR	NM_000492.4	c.263T>G	p.Leu88*	stop_gained	Exon 3 of 27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.263T>G	p.Leu88*	stop_gained	Exon 3 of 27	1	NM_000492.4	ENSP00000003084.6

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152244 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000192

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

GnomAD4 exome Cov.: 24

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152244 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74382

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000192

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:9

Revision: reviewed by expert panel

Submissions by phenotype

Cystic fibrosis Pathogenic:4

Mar 17, 2017

CFTR2

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: research

- -

Nov 03, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Leu88*) 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). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with cystic fibrosis (PMID: 1284542, 18955805, 23302613). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 53534). For these reasons, this variant has been classified as Pathogenic. -

Mar 18, 2016

Counsyl

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 09, 2018

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.L88* pathogenic mutation (also known as c.263T>G), located in coding exon 3 of the CFTR gene, results from a T to G substitution at nucleotide position 263. This changes the amino acid from a leucine to a stop codon within coding exon 3. This alteration and another nucleotide substitution with the same protein impact (c.263T>A) have been detected in patients reported to have cystic fibrosis with another pathogenic CFTR mutation reported as occurring in trans (Macek M et al. Hum. Mutat., 1992;1:501-2; Savov A et al. Hum. Mol. Genet., 1994 Jan;3:57-60; Ko JM et al. J. Korean Med. Sci., 2008 Oct;23:912-5). 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. -

not specified Pathogenic:1

May 25, 2018

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.263T>G (p.Leu88X) 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. The variant was absent in 245518 control chromosomes. c.263T>G has been reported in the literature in multiple individuals affected with Cystic Fibrosis (Savov 1995, Ko 2008, Tian 2016). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, and classified the variant as pathogenic and likely pathogenic. Based on the evidence outlined above, the variant was 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

- -

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

Jun 07, 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

Sep 17, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cystic fibrosis;C5924204:CFTR-related disorder Pathogenic:1

Aug 31, 2021

CFTR-France

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

the variant causes a phenotype but regarding our data, we can't formally attribute it to CF, CFTR-RD or both -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.63
CADD	Pathogenic	37
DANN	Uncertain	0.99
Eigen	Pathogenic	0.78
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Uncertain	0.96	D
Vest4		0.82
GERP RS		5.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs397508412; hg19: chr7-117149186;