rs1554392775

Positions:

• chr7-117614665-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP3_Moderate

The NM_000492.4(CFTR):​c.3420G>A​(p.Met1140Ile) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,460,352 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M1140L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 6.52

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain 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 chr7-117614664-T-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 53738.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.917

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CFTR	NM_000492.4	c.3420G>A	p.Met1140Ile	missense_variant	21/27	ENST00000003084.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CFTR	ENST00000003084.11	c.3420G>A	p.Met1140Ile	missense_variant	21/27	1	NM_000492.4	P2
	ENST00000456270.1	n.177+1564C>T		intron_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460352 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726504

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: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

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	Feb 24, 2022	This sequence change replaces methionine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 1140 of the CFTR protein (p.Met1140Ile). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CFTR-related conditions. ClinVar contains an entry for this variant (Variation ID: 439076). 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

Quest Diagnostics Nichols Institute San Juan Capistrano

Nov 01, 2016

- -

CFTR-related disorder Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Natera, Inc.

Feb 18, 2019

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.090
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.57	D;.;.;T;.
Eigen	Uncertain	0.30
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.98	D;D;D;D;D
M_CAP	Pathogenic	0.52	D
MetaRNN	Pathogenic	0.92	D;D;D;D;D
MetaSVM	Uncertain	0.12	D
MutationAssessor	Benign	1.6	L;.;.;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.67	T
PROVEAN	Benign	-0.48	N;.;.;N;.
REVEL	Uncertain	0.46
Sift	Benign	0.11	T;.;.;T;.
Sift4G	Uncertain	0.014	D;.;.;D;.
Polyphen		0.24	B;.;.;.;.
Vest4		0.73
MutPred		0.85		Gain of helix (P = 0.2294);.;.;.;.;
MVP		1.0
MPC		0.0041
ClinPred		0.84	D
GERP RS		5.9
Varity_R		0.66
gMVP		0.79

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: rs1554392775; hg19: chr7-117254719;