rs121908755

Positions:

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PM5PP3_ModeratePP5_Very_Strong

The NM_000492.4(CFTR):c.1646G>A(p.Ser549Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000397 in 1,611,174 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,drug response (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S549R) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000037 ( 0 hom. )

Consequence

CFTR
NM_000492.4 missense

Scores

Clinical Significance

Pathogenic; drug response reviewed by expert panel P:24O:1

Conservation

PhyloP100: 8.82

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PM1

In a modified_residue Phosphoserine (size 0) in uniprot entity CFTR_HUMAN there are 6 pathogenic changes around while only 0 benign (100%) in NM_000492.4

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr7-117587799-A-C is described in Lovd as [Pathogenic].

PP3

MetaRNN computational evidence supports a deleterious effect, 0.883

PP5

Variant 7-117587800-G-A is Pathogenic according to our data. Variant chr7-117587800-G-A is described in ClinVar as [Pathogenic, drug_response]. Clinvar id is 7116.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr7-117587800-G-A is described in Lovd as [Pathogenic]. Variant chr7-117587800-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CFTR	NM_000492.4 linkuse as main transcript	c.1646G>A	p.Ser549Asn	missense_variant	12/27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11 linkuse as main transcript	c.1646G>A	p.Ser549Asn	missense_variant	12/27	1	NM_000492.4	ENSP00000003084	P2	P13569-1

Frequencies

GnomAD3 genomes

AF:

0.0000657

AC:

AN:

152186

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000145

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000877

AC:

AN:

250912

Hom.:

AF XY:

0.000103

AC XY:

AN XY:

135576

show subpopulations

Gnomad AFR exome

AF:

0.000246

Gnomad AMR exome

AF:

0.000116

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000392

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000370

AC:

AN:

1458870

Hom.:

Cov.:

AF XY:

0.0000413

AC XY:

AN XY:

725934

show subpopulations

Gnomad4 AFR exome

AF:

0.000120

Gnomad4 AMR exome

AF:

0.000157

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000220

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000207

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000657

AC:

AN:

152304

Hom.:

Cov.:

AF XY:

0.0000537

AC XY:

AN XY:

74464

show subpopulations

Gnomad4 AFR

AF:

0.000144

Gnomad4 AMR

AF:

0.000196

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000335

Hom.:

Bravo

AF:

0.0000718

ESP6500AA

AF:

0.000454

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000107

AC:

ClinVar

Significance: Pathogenic; drug response

Submissions summary: Pathogenic:24Other:1

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

Cystic fibrosis

Pathogenic:11

Pathogenic, criteria provided, single submitter	clinical testing	Neuberg Centre For Genomic Medicine, NCGM	-	The c.1646G>A (p.Ser549Asn) missense variant in CFTR gene has been reported in individuals affected with cystic fibrosis, and is associated with pancreatic insufficiency (Ooi CY, Durie PR., 2015; Sharma et al., 2015). Experimental studies have shown that this variant causes defective channel gating, resulting in decreased chloride conductance (Sharma et al., 2015). This variant is reported with the allele frequency (0.008%) in the gnomAD and novel in 1000 genome database. This variant has been reported to the ClinVar database as Pathogenic. The amino acid Ser at position 549 is changed to a Asn changing protein sequence and it might alter its composition and physico-chemical properties. The amino acid change p.Ser549Asn in CFTR is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital	Oct 27, 2023	This heterozygous mis-sense variant is identified in a 4 month female with fever, respiratory infection, seizures, and epileptic encephalopathy. This nucleotide change is present in gnomAD database with a low allele frequency 0.0085% [PM2]. Insilico prediction [REVEL=0.91] predicts deleterious nature of this variant [PP3]. This variant is identified in trans [PM3] with a previously reported “Pathogenic” p.Phe508del variant . A clinvar entry for this variant is available. This variant is submitted to clinvar database [Variation ID: 7116] with “Pathogenic” interpretation by multiple submitter [PP5]. Based on the clinical correlation and available evidence, this variant is classified as "Pathogenic". -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Oct 18, 2019	NM_000492.3(CFTR):c.1646G>A(S549N) is classified as pathogenic in the context of cystic fibrosis and is associated with the classic form of the disease. Sources cited for classification include the following: PMID 1695717, 18456578, and 23974870. Classification of NM_000492.3(CFTR):c.1646G>A(S549N) is based on the following criteria: This is a well-established pathogenic variant in the literature that has been observed more frequently in patients with clinical diagnoses than in healthy populations. Please note: this variant was assessed in the context of healthy population screening. -
Pathogenic, criteria provided, single submitter	curation	CFTR-France	Jan 29, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 12, 2016	Variant summary: The c.1646G>A variant affects a conserved nucleotide, resulting in amino acid change from Ser to Asn. 4/5 in-silico tools predict this variant to be damaging. This variant is found in 13/120694 control chromosomes at a frequency of 0.0001077, which does not exceed maximal expected frequency of a pathogenic allele (0.0129603). This variant is a well-known pathogenic variant and has been reported in numerous CF patients. Variants affecting same amino acid, i.e. p.Ser549Arg, p.Ser549Ile, have been classified as pathogenic, suggesting Ser549 is critical for CFTR function. In addition, multiple clinical laboratories/reputable databases classified this variant as pathogenic. Taken together, this variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	May 02, 2022	The p.S549N pathogenic mutation (also known as c.1646G>A), located in coding exon 12 of the CFTR gene, results from a G to A substitution at nucleotide position 1646. The serine at codon 549 is replaced by asparagine, an amino acid with highly similar properties. This mutation was identified in a homozygous individual with an elevated sweat chloride level, growth failure, reduced lung function, and Psuedomonas aeruginosa colonization (Curtis A et al. J. Med. Genet., 1993 Feb;30:164-6). This mutation is associated with elevated sweat chloride levels and pancreatic insufficiency; in addition, a functional study found this mutation resulted in significantly decreased rates of chloride conductance compared to wild type (Sosnay PR et al. Nat Genet. 2013; 45(10):1160-7). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
Pathogenic, criteria provided, single submitter	clinical testing	Johns Hopkins Genomics, Johns Hopkins University	Sep 15, 2019	Disease-causing CFTR variant (previously reported for this patient by mass spectrometry genotyping). See www.CFTR2.org for phenotype information. -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 09, 2021	This variant was determined to be pathogenic according to ACMG Guidelines, 2015 [PMID:25741868]. -
Pathogenic, reviewed by expert panel	research	CFTR2	Mar 17, 2017	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Jul 26, 1990	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 09, 2024	This sequence change replaces serine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 549 of the CFTR protein (p.Ser549Asn). This variant is present in population databases (rs121908755, gnomAD 0.04%). This missense change has been observed in individual(s) with cystic fibrosis or congenital absence of the vas deferens (PMID: 1695717, 1721624, 7544319, 22658665, 23974870, 24440181, 25042876, 29360847). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is also known as c.1778G>A. ClinVar contains an entry for this variant (Variation ID: 7116). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CFTR protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects CFTR function (PMID: 22293084, 23974870, 25042876). This variant disrupts the p.Ser549 amino acid residue in CFTR. Other variant(s) that disrupt this residue have been determined to be pathogenic (Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

not provided

Pathogenic:7

Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Apr 13, 2019	The variant was found in at least one symptomatic individual. The variant predicted to have a damaging effect on the protein. The variant occurs in multiple cases with a lone recessive pathogenic/likely pathogenic variant in the same gene, and several have a phenotype known to be consistent with disease. The variant is damaging to protein function(s) relevant to disease mechanism. -
Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jul 30, 2018	- -
Pathogenic, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Aug 05, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Mar 26, 2021	- -
Pathogenic, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Apr 03, 2020	The CFTR c.1646G>A; p.Ser549Asn variant (rs121908755) is reported in the literature as a common variant in individuals affected with cystic fibrosis, and is associated with pancreatic insufficiency (Castellani 2008, Cutting 1990, Masica 2015, Sharma 2015, Sosnay 2013). This variant is also reported in individuals affected with CFTR-related disorders when found with a pathogenic-mild variant on the opposite chromosome (Masson 2013, Ooi 2012, Sharma 2014). This variant is reported in ClinVar (Variation ID: 7116), and is found in the general population with an overall allele frequency of 0.0085% (24/282312 alleles) in the Genome Aggregation Database. The serine at codon 549 is highly conserved and is located in the ATP binding site, and computational analyses (SIFT, PolyPhen-2) predict that this variant is deleterious. In vitro functional analyses demonstrate defects in channel gating and function (Sharma 2015, Yu 2012). Additionally, other variants at this codon (c.1645A>C; p.Ser549Arg, c.1647T>G; p.Ser549Arg) have been reported in individuals with cystic fibrosis and are considered pathogenic (Castellani 2008, Masica 2015, Sosnay 2013). Based on available information, the p.Ser549Asn variant is considered to be pathogenic. References: Castellani C et al. Consensus on the use and interpretation of cystic fibrosis mutation analysis in clinical practice. J Cyst Fibros. 2008 May;7(3):179-96. Cutting GR et al. A cluster of cystic fibrosis mutations in the first nucleotide-binding fold of the cystic fibrosis conductance regulator protein. Nature. 1990 Jul 26;346(6282):366-9. Masica DL et al. Missense variants in CFTR nucleotide-binding domains predict quantitative phenotypes associated with cystic fibrosis disease severity. Hum Mol Genet. 2015 Apr 1;24(7):1908-17. Masson E et al. A conservative assessment of the major genetic causes of idiopathic chronic pancreatitis: data from a comprehensive analysis of PRSS1, SPINK1, CTRC and CFTR genes in 253 young French patients. PLoS One. 2013 Aug 8;8(8):e73522. Ooi CY and Durie PR. Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations in pancreatitis. J Cyst Fibros. 2012 Sep;11(5):355-62. Sharma H et al. Heterogeneous spectrum of mutations in CFTR gene from Indian patients with congenital absence of the vas deferens and their association with cystic fibrosis genetic modifiers. Mol Hum Reprod. 2014 Sep;20(9):827-35. Sharma H et al. Function, pharmacological correction and maturation of new Indian CFTR gene mutations. J Cyst Fibros. 2015 Jan;14(1):34-41. Sosnay PR et al. Defining the disease liability of variants in the cystic fibrosis transmembrane conductance regulator gene. Nat Genet. 2013 Oct;45(10):1160-7. Yu H et al. Ivacaftor potentiation of multiple CFTR channels with gating mutations. J Cyst Fibros. 2012 May;11(3):237-45. -

CFTR-related disorder

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	Mar 16, 2023	The CFTR c.1646G>A variant is predicted to result in the amino acid substitution p.Ser549Asn. This variant has previously been reported to be causative for cystic fibrosis (Cutting et al. 1990. PubMed ID: 1695717; Hamosh et al. 1991. PubMed ID: 1721624; Brancolini et al. 1995. PubMed ID: 7544319; Watson et al. 2004. PubMed ID: 15371902; Sosnay et al. 2013. PubMed ID: 23974870; De Boeck et al. 2014. PubMed ID: 24440181; Sharma et al. 2014. PubMed ID: 25042876; Sutanto et al. 2018. PubMed ID: 29360847). This variant was also reported in at least two patients with pancreatitis (Ooi et al. 2012. PubMed ID: 22658665). This variant is reported in 0.039% of alleles in individuals of South Asian descent in gnomAD (http://gnomad.broadinstitute.org/variant/7-117227854-G-A). This variant is interpreted as pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Mar 17, 2017	- -

Cystic fibrosis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

- -

Hereditary pancreatitis

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Mendelics

May 04, 2022

- -

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

Feb 22, 2022

- -

Bronchiectasis with or without elevated sweat chloride 1

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Feb 27, 2024

- -

ivacaftor response - Efficacy

Other:1

drug response, reviewed by expert panel

curation

PharmGKB

Mar 24, 2021

PharmGKB Level of Evidence 1A: Level 1A clinical annotations describe variant-drug combinations that have variant-specific prescribing guidance available in a current clinical guideline annotation or an FDA-approved drug label annotation. Annotations of drug labels or clinical guidelines must give prescribing guidance for specific variants (e.g. CYP2C9*3, HLA-B*57:01) or provide mapping from defined allele functions to diplotypes and phenotypes to be used as supporting evidence for a level 1A clinical annotation. Level 1A clinical annotations must also be supported by at least one publication in addition to a clinical guideline or drug label with variant-specific prescribing guidance. Drug-variant association: Efficacy

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.95

BayesDel_addAF

Uncertain

0.13

BayesDel_noAF

Pathogenic

0.26

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.96

D;.;D;.

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Uncertain

0.97

LIST_S2

Pathogenic

1.0

D;D;D;D

M_CAP

Pathogenic

0.84

MetaRNN

Pathogenic

0.88

D;D;D;D

MetaSVM

Pathogenic

0.98

MutationAssessor

Pathogenic

4.7

H;.;.;.

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.70

PROVEAN

Uncertain

-2.8

D;.;D;.

REVEL

Pathogenic

0.91

Sift

Pathogenic

0.0

D;.;D;.

Sift4G

Pathogenic

0.0010

D;.;D;.

Polyphen

1.0

D;.;.;.

Vest4

0.98

MVP

1.0

MPC

0.018

ClinPred

0.97

GERP RS

5.1

Varity_R

0.99

gMVP

0.97

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over