rs397508350

Positions:

• chr7-117592362-T-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.2195T>G​(p.Leu732Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,770 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: 0.0000014 (0 hom.)
• Consequence: CFTR NM_000492.4 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:13
• Conservation: PhyloP100: -0.0650

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 7-117592362-T-G is Pathogenic according to our data. Variant chr7-117592362-T-G is described in ClinVar as [Pathogenic]. Clinvar id is 53451.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr7-117592362-T-G is described in Lovd as [Pathogenic]. Variant chr7-117592362-T-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CFTR	NM_000492.4	c.2195T>G	p.Leu732Ter	stop_gained	14/27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.2195T>G	p.Leu732Ter	stop_gained	14/27	1	NM_000492.4	ENSP00000003084	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251276 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135838

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

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: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461770 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727180

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:13

Revision: reviewed by expert panel

Submissions by phenotype

Cystic fibrosis Pathogenic:7

Pathogenic, reviewed by expert panel	research	CFTR2	Mar 17, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 08, 2023	This sequence change creates a premature translational stop signal (p.Leu732*) 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 present in population databases (rs397508350, gnomAD 0.0009%). This premature translational stop signal has been observed in individual(s) with CFTR-related conditions (PMID: 9003508, 23974870). ClinVar contains an entry for this variant (Variation ID: 53451). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Jan 26, 2024	The p.L732* pathogenic mutation (also known as c.2195T>G), located in coding exon 14 of the CFTR gene, results from a T to G substitution at nucleotide position 2195. This changes the amino acid from a leucine to a stop codon within coding exon 14. In one study, this mutation was reported in an individual with congenital bilateral absence of the vas deferens (CBAVD), recurrent bronchitis, and a few gastrointestinal issues in conjunction with a 5T allele (Kanavakis E et al. Mol Hum Reprod, 1998 Apr;4:333-7). In another study, this mutation was seen along with a second CFTR variant in an individual with failure to thrive, chronic cough, chronic sinusitis, and elevated sweat chloride levels (McGinniss MJ et al. Hum Genet, 2005 Dec;118:331-8). This variant is assoicated with elevated sweat chloride levels, pancreatic insufficiency, and decreased lung function (Sosnay PR et al. Nat Genet, 2013 Oct;45:1160-7). 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. -
Pathogenic, criteria provided, single submitter	curation	CFTR-France	Jan 29, 2018	- -
Pathogenic, no assertion criteria provided	clinical testing	Counsyl	Jul 28, 2015	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jun 25, 2016	Variant summary: The CFTR c.2195T>G (p.Leu732X) variant results in a premature termination codon, predicted to cause a truncated or absent CFTR protein due to nonsense mediated decay, which are commonly known mechanisms for disease. A truncation of this variant at Leu732 would eliminate part of the CFTR regulator domain, the N terminal transmembrane domain, the AAA+ ATPase domain, and the P-loop NTPase fold domain. Consequently, one in silico tool predicts a damaging outcome for this variant. This variant was found in 1/120718 control chromosomes at a frequency of 0.0000083, which does not exceed the estimated maximal expected allele frequency of a pathogenic CFTR variant (0.0129603). It was reported in many CF patients with at least one patient being homozygous for the variant, indicating pathogenicity. Furthermore, truncations downstream of this position have been classified as pathogenic by our laboratory (e.g. p.Trp1089X, p.Tyr1092X). Additionally, at least one database classified the variant as pathogenic/CF-causing. Taken together, this variant is classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Mendelics	Nov 05, 2018	- -

not provided Pathogenic:4

Pathogenic, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Clinical Genetics and Genomics, Karolinska University Hospital	Jul 13, 2018	- -
Pathogenic, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Mar 10, 2022	PP4, PP5, PM2, PM3_very_strong, PVS1 -

CFTR-related disorder Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Natera, Inc.

Mar 17, 2017

- -

Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Jan 29, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.26
CADD	Pathogenic	27
DANN	Benign	0.97
Eigen	Benign	-0.20
Eigen_PC	Benign	-0.57
FATHMM_MKL	Benign	0.073	N
MutationTaster	Benign	1.0	A;A
Vest4		0.81
GERP RS		-4.7

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: rs397508350; hg19: chr7-117232416;