7-117534318-G-A

Position:

• chr7-117534318-G-A

Variant summary

Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PS1 PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The ENST00000003084.11(CFTR):​c.532G>A​(p.Gly178Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000825 in 1,453,780 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic,drug response (★★★). Another nucleotide change resulting in same amino acid change has been previously reported as Pathogenicin ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G178E) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000083 (0 hom.)
• Consequence: CFTR ENST00000003084.11 missense
• Clinical Significance: Pathogenic; drug response reviewed by expert panel P:15 O:1
• Conservation: PhyloP100: 9.08

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 22 ACMG points.

• PS1: Transcript ENST00000003084.11 (CFTR) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar as 1685614
• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 14 uncertain in ENST00000003084.11
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr7-117534319-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 53992.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=2}.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 7-117534318-G-A is Pathogenic according to our data. Variant chr7-117534318-G-A is described in ClinVar as [Pathogenic, drug_response]. Clinvar id is 48692.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr7-117534318-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.532G>A	p.Gly178Arg	missense_variant	5/27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.532G>A	p.Gly178Arg	missense_variant	5/27	1	NM_000492.4	ENSP00000003084	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000160 AC: 4 AN: 250684 Hom.: 0 AF XY: 0.0000148 AC XY: 2 AN XY: 135552

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: 0.0000353

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000825 AC: 12 AN: 1453780 Hom.: 0 Cov.: 26 AF XY: 0.00000691 AC XY: 5 AN XY: 723782

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: 0.0000109

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Pathogenic; drug response

Submissions summary: Pathogenic:15 Other:1

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	Dec 04, 2023	This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 178 of the CFTR protein (p.Gly178Arg). This variant is present in population databases (rs80282562, gnomAD 0.003%). This missense change has been observed in individual(s) with cystic fibrosis (PMID: 1710599, 15638824, 23974870, 29133775). 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: 48692). 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: 9305991). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Apr 19, 2023	The p.G178R pathogenic mutation (also known as c.532G>A and 664G>A), located in coding exon 5 of the CFTR gene, results from a G to A substitution at nucleotide position 532. The glycine at codon 178 is replaced by arginine, an amino acid with dissimilar properties. This mutation was originally described in a Canadian family with cystic fibrosis (Zielenski J et al, Genomics 1991 May; 10(1):229-35). Subsequently, a homozygous p.G178R mutation was identified in a French individual with cystic fibrosis (Claustres M et al, Hum. Mutat. 2000; 16(2):143-56). In addition, this pathogenic mutation was found in 50 individuals with cystic fibrosis and was associated with high sweat chloride levels and pancreatic insufficiency (Sosnay PR et al, Nat. Genet. 2013 Oct; 45(10):1160-7). In vitro functional studies showed that G178R mutant protein is processed and matures normally, but has reduced chloride channel activity (Seibert FS et al, Biochemistry 1997 Sep; 36(39):11966-74; Sosnay PR et al, Nat. Genet. 2013 Oct; 45(10):1160-7). Based on the available evidence, this alteration is classified as a pathogenic mutation. -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Oct 24, 2022	Variant summary: CFTR c.532G>A (p.Gly178Arg) results in a non-conservative amino acid change located in the ABC transporter type 1, transmembrane domain of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. One computational tool predict the variant creates a 3' acceptor site. Consistent with this prediction, one functional study showed that this variant led to a significant skipping of exon 5 (Raynal_2013). The variant allele was found at a frequency of 1.2e-05 in 168188 control chromosomes. c.532G>A has been reported in the literature in multiple individuals affected with Cystic Fibrosis (Zielenski_1991, Cremonesi_1992, Heim_2001, Sugarman_2004, Ooi_2012, Sosnay_2013, DeBoeck_2014). These data indicate that the variant is very likely to be associated with disease. Multiple publications report experimental evidence evaluating an impact on protein function (Seibert_1997, Choi_2001, Yu_2012, Sosnay_2013). The most pronounced variant effect results in <10% of normal activity. Eleven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	curation	CFTR-France	Jan 29, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Dec 04, 2019	NM_000492.3(CFTR):c.532G>A(G178R) is classified as pathogenic in the context of cystic fibrosis and is associated with classic disease. Sources cited for classification include the following: PMID 18456578, 9305991, 23381846 and 23974870. Classification of NM_000492.3(CFTR):c.532G>A(G178R) 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	clinical testing	Johns Hopkins Genomics, Johns Hopkins University	Dec 01, 2023	Disease-causing CFTR variant. See www.CFTR2.org for phenotype information. -

CFTR-related disorder Pathogenic:2

Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Mar 17, 2017	- -
Pathogenic, no assertion criteria provided	clinical testing	PreventionGenetics, part of Exact Sciences	Mar 22, 2024	The CFTR c.532G>A variant is predicted to result in the amino acid substitution p.Gly178Arg. This variant, also known as c.664G>A in literature, has been reported along with a second pathogenic variant in multiple individuals with Cystic Fibrosis (Zielenski et al. 1991. PubMed ID: 1710599; Ooi et al. 2012. PubMed ID: 22658665; Raraigh et al. 2021. PubMed ID: 34782259; Sosnay PR et al 2013. PubMed ID: 23974870; https://cftr2.org/mutation/scientific/G178R/). In vitro functional studies suggest this variant impairs CFTR chloride channel function (Seibert et al. 1997. PubMed ID: 9305991; Choi et al. 2001. PubMed ID: 11242048). This variant is reported in 0.0035% of alleles in individuals of European (non-Finnish) descent in gnomAD. This variant is interpreted as pathogenic. -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	May 21, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	May 13, 2021	- -

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

Oct 31, 2018

- -

Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Nov 27, 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	0.76
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.94	D;.;.;.
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;D;D;D
M_CAP	Pathogenic	0.95	D
MetaRNN	Pathogenic	0.99	D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.0	M;.;.;M
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-6.6	D;.;.;.
REVEL	Pathogenic	0.97
Sift	Uncertain	0.0010	D;.;.;.
Sift4G	Uncertain	0.0020	D;.;.;.
Polyphen		1.0	D;.;.;.
Vest4		0.93
MutPred		0.97		Gain of MoRF binding (P = 0.0084);Gain of MoRF binding (P = 0.0084);Gain of MoRF binding (P = 0.0084);Gain of MoRF binding (P = 0.0084);
MVP		1.0
MPC		0.016
ClinPred		0.98	D
GERP RS		5.5
Varity_R		0.99
gMVP		0.98

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: rs80282562; hg19: chr7-117174372;