rs121908753

Positions:

• chr7-117540285-G-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000492.4(CFTR):​c.1055G>A​(p.Arg352Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000178 in 1,461,714 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. R352W) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000018 (0 hom.)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Pathogenic; drug response reviewed by expert panel P:19 O:1
• Conservation: PhyloP100: 9.42

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.

• PM1: In a transmembrane_region Helical; Name=6 (size 18) in uniprot entity CFTR_HUMAN there are 9 pathogenic changes around while only 1 benign (90%) 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 chr7-117540284-C-T is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.964
• PP5: Variant 7-117540285-G-A is Pathogenic according to our data. Variant chr7-117540285-G-A is described in ClinVar as [Pathogenic, drug_response]. Clinvar id is 7198.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr7-117540285-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CFTR	NM_000492.4	c.1055G>A	p.Arg352Gln	missense_variant	8/27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.1055G>A	p.Arg352Gln	missense_variant	8/27	1	NM_000492.4	ENSP00000003084	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000239 AC: 6 AN: 251124 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135714

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000131

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000178 AC: 26 AN: 1461714 Hom.: 0 Cov.: 31 AF XY: 0.0000193 AC XY: 14 AN XY: 727162

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000464

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.000136 Hom.: 0

Bravo AF: 0.0000340

ExAC AF: 0.0000247 AC: 3

EpiCase AF: 0.0000545

EpiControl AF: 0.0000593

ClinVar

Significance: Pathogenic; drug response

Submissions summary: Pathogenic:19 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Cystic fibrosis Pathogenic:11

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Oct 07, 2019	Variant summary: CFTR c.1055G>A (p.Arg352Gln) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.4e-05 in 251124 control chromosomes (gnomAD). c.1055G>A has been reported in the literature in multiple individuals affected with Cystic Fibrosis (e.g. Dupuis_2015, Shackelton_1994, Sosnay_2013). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function, and demonstrated that the variant leads to defective chloride channel function (Sosnay 2013). Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, and all of them classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, reviewed by expert panel	research	CFTR2	Mar 17, 2017	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Jan 01, 1993	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 09, 2023	This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 352 of the CFTR protein (p.Arg352Gln). This variant is present in population databases (rs121908753, gnomAD 0.01%). This missense change has been observed in individual(s) with cystic fibrosis (PMID: 7544319, 20522854, 27086061, 28646244). ClinVar contains an entry for this variant (Variation ID: 7198). 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%. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	May 10, 2023	The p.R352Q pathogenic mutation (also known as c.1055G>A), located in coding exon 8 of the CFTR gene, results from a G to A substitution at nucleotide position 1055. The arginine at codon 352 is replaced by glutamine, an amino acid with highly similar properties. This mutation was first reported in an individual with pancreatic sufficient cystic fibrosis (CF) and an unknown variant on the other chromosome (Cremonesi L et al. Hum. Mutat., 1992;1:314-9). In two additional studies, p.R352Q was reported in conjunction with p.F508del in an individual with CF and an individual with idiopathic chronic pancreatitis (Zitkiewicz E et al. PLoS ONE, 2014 Mar;9:e89094; Steiner B et al. Hum. Mutat., 2011 Aug;32:912-20). This mutation is associated with pancreatic sufficiency and elevated sweat chloride levels (Sosnay PR et al. Nat. Genet., 2013 Oct;45:1160-7). In a functional study using a Xenopus laevis oocyte model, alterations affecting the positive charge at codon 352 (p.R352A, p.R352E, p.R352Q) were observed to alter pore structure by disrupting the interaction between R352 and D993 (Cui G et al. J. Membr. Biol., 2008 Mar;222:91-106). 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	Jan 06, 2020	Previously reported disease-causing CFTR variant. See www.CFTR2.org for phenotype information. -
Pathogenic, criteria provided, single submitter	clinical testing	Genome Diagnostics Laboratory, The Hospital for Sick Children	Aug 14, 2019	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Neuberg Centre For Genomic Medicine, NCGM	Jun 02, 2023	The observed frameshift variant c.3871del(p.Ala1291ProfsTer39) in the ATP7B gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. This variant is absent in the gnomAD Exomes. This variant causes a frameshift starting with codon Alanine 1291, changes this amino acid to Proline residue, and creates a premature Stop codon at position 39 of the new reading frame, denoted p.Ala1291ProfsTer39. This variant is predicted to cause loss of normal protein function through protein truncation. Loss of function variants have been previously reported to be disease causing. For these reasons, this variant has been classified as Likely Pathogenic. -
Pathogenic, criteria provided, single submitter	curation	CFTR-France	Jan 29, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Nov 12, 2019	NM_000492.3(CFTR):c.1055G>A(R352Q) is classified as pathogenic in the context of cystic fibrosis and is associated with the non-classic form of disease. Sources cited for classification include the following: PMID 18456578 and 23974870. Classification of NM_000492.3(CFTR):c.1055G>A(R352Q) 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.‚Äã -
Pathogenic, criteria provided, single submitter	clinical testing	Mendelics	Nov 05, 2018	- -

not provided Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Greenwood Genetic Center Diagnostic Laboratories, Greenwood Genetic Center	Feb 01, 2021	PS3, PM3_Supporting, PP3, PM1, PM2 -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Apr 13, 2019	The variant was found in a symptomatic patient. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is damaging. The variant occurs with multiple lone recessive pathogenic variants in the same gene. Functional studies have shown that this variant has a deleterious effect on protein function. -
Pathogenic, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Aug 16, 2022	The CFTR c.1055G>A; p.Arg352Gln variant (rs121908753) is reported in the literature in several individuals affected with cystic fibrosis (Masson 2013, Ooi 2012, Sosnay 2013). This variant is also reported in ClinVar (Variation ID: 7198), and is only observed on six alleles in the Genome Aggregation Database, indicating it is not a common polymorphism. The arginine at codon 352 is highly conserved, and computational analyses predict that this variant is deleterious (REVEL: 0.804). Additionally, functional assays demonstrate reduced protein function (Van Goor 2014). Based on available information, this variant is considered to be pathogenic. References 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. PMID: 23951356. Ooi CY et al. Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations in pancreatitis. J Cyst Fibros. 2012 Sep;11(5):355-62. PMID: 22658665. 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. PMID: 23974870. Van Goor F et al. Effect of ivacaftor on CFTR forms with missense mutations associated with defects in protein processing or function. J Cyst Fibros. 2014 Jan;13(1):29-36. PMID: 23891399. -

CFTR-related disorder Pathogenic:2

Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Mar 17, 2017	- -
Pathogenic, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, The Hospital for Sick Children	Aug 14, 2019	- -

Cystic fibrosis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

-

- -

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

Oct 31, 2018

- -

Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Oct 11, 2023

- -

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	0.63
BayesDel_addAF	Pathogenic	0.28	D
BayesDel_noAF	Pathogenic	0.40
CADD	Pathogenic	31
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.40	T;.;.;T;.
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	D;D;D;D;D
M_CAP	Pathogenic	0.74	D
MetaRNN	Pathogenic	0.96	D;D;D;D;D
MetaSVM	Uncertain	0.72	D
MutationAssessor	Benign	1.9	M;.;.;.;M
MutationTaster	Benign	1.0	A;A
PrimateAI	Uncertain	0.58	T
PROVEAN	Benign	-1.1	N;.;.;N;.
REVEL	Pathogenic	0.80
Sift	Uncertain	0.0070	D;.;.;D;.
Sift4G	Pathogenic	0.0	D;.;.;D;.
Polyphen		1.0	D;.;.;.;.
Vest4		0.85
MutPred		0.89		Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);.;Loss of helix (P = 0.0558);
MVP		1.0
MPC		0.0039
ClinPred		0.70	D
GERP RS		5.3
Varity_R		0.54
gMVP		0.90

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs121908753; hg19: chr7-117180339; COSMIC: COSV50042446;