7-117603644-G-C

Position:

• chr7-117603644-G-C

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.2770G>C​(p.Asp924His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,918 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. D924N) has been classified as Pathogenic.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 9.76

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a domain ABC transmembrane type-1 2 (size 296) in uniprot entity CFTR_HUMAN there are 53 pathogenic changes around while only 8 benign (87%) 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 chr7-117603644-G-A is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.922

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CFTR	NM_000492.4	c.2770G>C	p.Asp924His	missense_variant	17/27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.2770G>C	p.Asp924His	missense_variant	17/27	1	NM_000492.4	ENSP00000003084.6

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152164 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: 0.00

Gnomad OTH AF: 0.000478

GnomAD4 exome AF: 0.00000410 AC: 6 AN: 1461754 Hom.: 0 Cov.: 32 AF XY: 0.00000550 AC XY: 4 AN XY: 727184

Gnomad4 AFR exome AF: 0.0000598

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: 0.00000657 AC: 1 AN: 152164 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74326

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: 0.00

Gnomad4 OTH AF: 0.000478

Bravo AF: 0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cystic fibrosis Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jun 19, 2023	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. 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: 565487). This variant has not been reported in the literature in individuals affected with CFTR-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces aspartic acid, which is acidic and polar, with histidine, which is basic and polar, at codon 924 of the CFTR protein (p.Asp924His). -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 05, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jul 26, 2023	The p.D924H variant (also known as c.2770G>C), located in coding exon 17 of the CFTR gene, results from a G to C substitution at nucleotide position 2770. The aspartic acid at codon 924 is replaced by histidine, an amino acid with similar properties. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

CFTR-related disorder Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Natera, Inc.

Feb 15, 2019

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Jul 01, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.28	D
BayesDel_noAF	Pathogenic	0.17
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.63	D;.;.;T;.
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.95	D;D;D;D;D
M_CAP	Pathogenic	0.80	D
MetaRNN	Pathogenic	0.92	D;D;D;D;D
MetaSVM	Uncertain	0.74	D
MutationAssessor	Uncertain	2.5	M;.;.;.;.
PrimateAI	Uncertain	0.56	T
PROVEAN	Benign	-1.2	N;.;.;N;.
REVEL	Uncertain	0.64
Sift	Uncertain	0.014	D;.;.;D;.
Sift4G	Pathogenic	0.0010	D;.;.;D;.
Polyphen		1.0	D;.;.;.;.
Vest4		0.76
MutPred		0.78		Gain of catalytic residue at L926 (P = 0.0468);.;.;.;.;
MVP		1.0
MPC		0.016
ClinPred		0.96	D
GERP RS		5.8
Varity_R		0.88
gMVP		0.85

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

LitVar

Other links and lift over

dbSNP: rs201759207; hg19: chr7-117243698;