rs1397796355

chr7-117667005-T-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000492.4(CFTR):c.4340T>A(p.Val1447Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,613,612 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. 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. V1447M) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 2.31

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 Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.11450112).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CFTR	NM_000492.4	c.4340T>A	p.Val1447Glu	missense_variant	27/27	ENST00000003084.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CFTR	ENST00000003084.11	c.4340T>A	p.Val1447Glu	missense_variant	27/27	1	NM_000492.4	P2

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 151880 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000726

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: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461732 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727166

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: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 151880 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74182

Gnomad4 AFR AF: 0.0000726

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: 0.00

Bravo AF: 0.0000151

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cystic fibrosis Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 05, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Aug 26, 2021	This sequence change replaces valine with glutamic acid at codon 1447 of the CFTR protein (p.Val1447Glu). The valine residue is weakly conserved and there is a moderate physicochemical difference between valine and glutamic acid. This variant is not present in population databases (ExAC no frequency). 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. -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Mar 01, 2019

The CFTR c.4340T>A; p.Val1447Glu variant (rs1397796355), to our knowledge, is not reported in the medical literature but is reported in ClinVar (Variation ID: 455781). This variant is absent from general population databases (Exome Variant Server, Genome Aggregation Database), indicating it is not a common polymorphism. The valine at codon 1447 is weakly conserved, but computational analyses (SIFT: damaging, PolyPhen-2: benign) predict conflicting effects of this variant on protein structure/function. Given the lack of clinical and functional data, the significance of the p.Val1447Glu variant is uncertain at this time. -

CFTR-related disorder Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Natera, Inc.

May 01, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Uncertain	0.054	T
BayesDel_noAF	Benign	-0.16
Cadd	Benign	20
Dann	Benign	0.96
DEOGEN2	Benign	0.40	T;T;.
Eigen	Benign	-0.63
Eigen_PC	Benign	-0.56
FATHMM_MKL	Benign	0.62	D
LIST_S2	Benign	0.84	T;T;T
M_CAP	Benign	0.066	D
MetaRNN	Benign	0.11	T;T;T
MetaSVM	Benign	-0.43	T
MutationAssessor	Benign	0.69	N;.;.
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.28	T
PROVEAN	Benign	-1.2	N;N;.
REVEL	Benign	0.18
Sift	Uncertain	0.0040	D;D;.
Sift4G	Uncertain	0.0020	D;D;.
Polyphen		0.013	B;.;.
Vest4		0.19
MutPred		0.42		Loss of stability (P = 0.0076);.;.;
MVP		0.97
MPC		0.0032
ClinPred		0.32	T
GERP RS		1.7
Varity_R		0.15
gMVP		0.54

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: rs1397796355; hg19: chr7-117307059;