rs74503330

Positions:

• chr7-117642472-G-A

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1 PM2 PP3_Strong PP5_Very_Strong

The NM_000492.4(CFTR):​c.3752G>A​(p.Ser1251Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000991 in 1,613,738 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. S1251T) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000096 (0 hom.)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Pathogenic; drug response reviewed by expert panel P:16 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]

(HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 9 uncertain in NM_000492.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.987
• PP5: Variant 7-117642472-G-A is Pathogenic according to our data. Variant chr7-117642472-G-A is described in ClinVar as [Pathogenic, drug_response]. Clinvar id is 7217.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr7-117642472-G-A is described in Lovd as [Pathogenic]. Variant chr7-117642472-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CFTR	NM_000492.4	c.3752G>A	p.Ser1251Asn	missense_variant	23/27	ENST00000003084.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CFTR	ENST00000003084.11	c.3752G>A	p.Ser1251Asn	missense_variant	23/27	1	NM_000492.4	P2
	ENST00000456270.1	n.65+4879C>T		intron_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152210 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: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.000478

GnomAD3 exomes AF: 0.00000797 AC: 2 AN: 251074 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135690

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: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.00000958 AC: 14 AN: 1461410 Hom.: 0 Cov.: 32 AF XY: 0.00000825 AC XY: 6 AN XY: 726996

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000108

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152328 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74486

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.000473

Bravo AF: 0.0000113

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic; drug response

Submissions summary: Pathogenic:16 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Cystic fibrosis Pathogenic:8

Pathogenic, no assertion criteria provided	literature only	OMIM	Jan 01, 1993	- -
Pathogenic, criteria provided, single submitter	clinical testing	Mendelics	Nov 05, 2018	- -
Pathogenic, criteria provided, single submitter	curation	CFTR-France	Jan 29, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Dec 07, 2019	NM_000492.3(CFTR):c.3752G>A(S1251N) is classified as pathogenic in the context of cystic fibrosis and is associated with the classic form of disease. Sources cited for classification include the following: PMID 23974870. Classification of NM_000492.3(CFTR):c.3752G>A(S1251N) 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	Ambry Genetics	Sep 21, 2022	The p.S1251N pathogenic mutation (also known as c.3752G>A and 3884G>A), located in coding exon 23 of the CFTR gene, results from a G to A substitution at nucleotide position 3752. The serine at codon 1251 is replaced by asparagine. This mutation was first reported in two individuals with pancreatic insufficiency (PI), severe pulmonary disease, and gastrointestinal disease; both individuals carried the p.F508C alteration in cis and the p.F508del mutation in trans (Kälin N, et al. Hum Mutat. 1992; 1(3):204-10). This mutation is associated with elevated sweat chloride levels, lung disease, and PI; in addition, a functional study found this mutation resulted in significantly decreased rates of chloride conductance (Sosnay PR, et al. Nat Genet. 2013; 45(10):1160-7, Supplementary Table). Based on the supporting evidence, p.S1251N is interpreted as a disease-causing mutation. -
Pathogenic, criteria provided, single submitter	clinical testing	Genome Diagnostics Laboratory, The Hospital for Sick Children	Oct 02, 2019	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jul 29, 2023	This missense change has been observed in individuals with cystic fibrosis (PMID: 1284535, 17481968, 23974870, 26989879). For these reasons, this variant has been classified as Pathogenic. Experimental studies have shown that this missense change affects CFTR function (PMID: 22293084). 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. ClinVar contains an entry for this variant (Variation ID: 7217). This variant is present in population databases (rs74503330, gnomAD 0.006%). This sequence change replaces serine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 1251 of the CFTR protein (p.Ser1251Asn). -
Pathogenic, reviewed by expert panel	research	CFTR2	Mar 17, 2017	- -

not provided Pathogenic:4

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	Quest Diagnostics Nichols Institute San Juan Capistrano	Apr 04, 2017	- -
Pathogenic, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -

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	Oct 02, 2019	- -

not specified Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Dec 11, 2017

Variant summary: The CFTR c.3752G>A (p.Ser1251Asn) variant involves the alteration of a conserved nucleotide. 4/5 in silico tools predict a damaging outcome for this variant. This variant was found in 2/240702 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). The variant has been reported in numerous CF patients worldwide and functional studies showed variant with defective channel opening and chloride transport (<10% normal CFTR). In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as pathogenic. Taken together, this variant is classified as pathogenic. -

Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Jan 13, 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	0.93
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Pathogenic	0.23
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.95	D;D;.
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D;D;D
M_CAP	Pathogenic	0.59	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.7	H;.;.
MutationTaster	Benign	1.0	A;A
PrimateAI	Uncertain	0.68	T
PROVEAN	Uncertain	-2.5	N;N;.
REVEL	Pathogenic	0.91
Sift	Uncertain	0.0020	D;D;.
Sift4G	Pathogenic	0.0010	D;D;.
Polyphen		0.99	D;.;.
Vest4		0.98
MutPred		0.97		Loss of disorder (P = 0.0674);.;.;
MVP		1.0
MPC		0.016
ClinPred		0.98	D
GERP RS		5.2
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

Other links and lift over

dbSNP: rs74503330; hg19: chr7-117282526;