rs749432776

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1PP2

The NM_000492.4(CFTR):c.256A>G(p.Ile86Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000038 in 1,578,918 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I86N) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000035 ( 0 hom. )

Consequence

CFTR
NM_000492.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 1.48

Publications

1 publications found

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 Gene-Disease associations (from GenCC):

cystic fibrosis
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, Orphanet
congenital bilateral absence of vas deferens
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
hereditary chronic pancreatitis
Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

CFTR links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM1

In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 26 uncertain in NM_000492.4

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 197 curated pathogenic missense variants (we use a threshold of 10). The gene has 46 curated benign missense variants. Gene score misZ: -3.1397 (below the threshold of 3.09). Trascript score misZ: -1.0868 (below the threshold of 3.09). GenCC associations: The gene is linked to hereditary chronic pancreatitis, cystic fibrosis, congenital bilateral absence of vas deferens.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CFTR	NM_000492.4 link	c.256A>G	p.Ile86Val	missense_variant	Exon 3 of 27	ENST00000003084.11	NP_000483.3	P13569-1A0A024R730

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11 link	c.256A>G	p.Ile86Val	missense_variant	Exon 3 of 27	1	NM_000492.4	ENSP00000003084.6		P13569-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152198

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000120

AC:

AN:

250834

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000868

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000350

AC:

AN:

1426720

Hom.:

Cov.:

AF XY:

0.00000140

AC XY:

AN XY:

712358

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

32830

American (AMR)

AF:

0.000112

AC:

AN:

44686

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25908

East Asian (EAS)

AF:

0.00

AC:

AN:

39496

South Asian (SAS)

AF:

0.00

AC:

AN:

85590

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53066

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5676

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1080388

Other (OTH)

AF:

0.00

AC:

AN:

59080

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.465

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152198

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74346

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41464

American (AMR)

AF:

0.0000655

AC:

AN:

15268

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5208

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68022

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cystic fibrosis

Uncertain:2

Aug 31, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces isoleucine with valine at codon 86 of the CFTR protein (p.Ile86Val). The isoleucine residue is moderately conserved and there is a small physicochemical difference between isoleucine and valine. This variant is present in population databases (rs749432776, ExAC 0.02%). This variant has not been reported in the literature in individuals affected with CFTR-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Jun 24, 2023

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.I86V variant (also known as c.256A>G), located in coding exon 3 of the CFTR gene, results from an A to G substitution at nucleotide position 256. The isoleucine at codon 86 is replaced by valine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

CFTR-related disorder

Uncertain:2

May 24, 2018

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Mar 06, 2024

PreventionGenetics, part of Exact Sciences

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

The CFTR c.256A>G variant is predicted to result in the amino acid substitution p.Ile86Val. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.0087% of alleles in individuals of Latino descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

not specified

Uncertain:1

Mar 22, 2025

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

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.076

BayesDel_addAF

Uncertain

0.020

BayesDel_noAF

Uncertain

-0.010

CADD

Benign

(source)

DANN

Benign

0.97

DEOGEN2

Uncertain

0.47

.;T;.;.;T;.

Eigen

Benign

-0.28

Eigen_PC

Benign

-0.12

FATHMM_MKL

Uncertain

0.79

LIST_S2

Benign

0.83

T;D;D;D;D;D

M_CAP

Pathogenic

0.35

MetaRNN

Uncertain

0.52

D;D;D;D;D;D

MetaSVM

Uncertain

0.79

MutationAssessor

Benign

0.23

.;N;.;.;.;N

PhyloP100

1.5

PrimateAI

Uncertain

0.59

PROVEAN

Benign

-0.58

N;N;.;.;N;.

REVEL

Uncertain

0.45

Sift

Benign

0.078

T;T;.;.;T;.

Sift4G

Benign

0.16

T;T;.;.;T;.

Polyphen

0.0010

.;B;.;.;.;.

Vest4

0.41

MutPred

0.69

.;Loss of MoRF binding (P = 0.1247);Loss of MoRF binding (P = 0.1247);Loss of MoRF binding (P = 0.1247);Loss of MoRF binding (P = 0.1247);Loss of MoRF binding (P = 0.1247);

MVP

0.99

MPC

0.0045

ClinPred

0.15

GERP RS

3.1

Varity_R

0.13

gMVP

0.71

Mutation Taster

=70/30

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over