chr7-117603735-A-G

Variant names:

• chr7-117603735-A-G
• rs397508446
• NM_000492.4:c.2861A>G

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 5P and 2B. PM1 PM2 PP2 BP4_Moderate

The NM_000492.4(CFTR):​c.2861A>G​(p.His954Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,738 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 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. H954Y) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.34
• Publications: 1 publications found

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)

ACMG classification

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

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 15 uncertain in NM_000492.4
• PM2: Very rare variant in population databases, with high coverage
• 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.26043147).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CFTR	NM_000492.4	c.2861A>G	p.His954Arg	missense_variant	Exon 17 of 27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.2861A>G	p.His954Arg	missense_variant	Exon 17 of 27	1	NM_000492.4	ENSP00000003084.6

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461738 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727164

African (AFR) AF: 0.00 AC: 0 AN: 33466

American (AMR) AF: 0.00 AC: 0 AN: 44696

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26126

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111928

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cystic fibrosis Uncertain:1

Apr 14, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.H954R variant (also known as c.2861A>G), located in coding exon 17 of the CFTR gene, results from an A to G substitution at nucleotide position 2861. The histidine at codon 954 is replaced by arginine, an amino acid with highly similar properties. This amino acid position is not well conserved in available vertebrate species, and arginine is the reference amino acid in other 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.060
BayesDel_addAF	Uncertain	0.093	D
BayesDel_noAF	Benign	-0.10
CADD	Benign	12
DANN	Benign	0.93
DEOGEN2	Uncertain	0.67	D;.;.;T;.
Eigen	Benign	-0.44
Eigen_PC	Benign	-0.30
FATHMM_MKL	Benign	0.66	D
LIST_S2	Benign	0.80	T;T;T;T;T
M_CAP	Benign	0.084	D
MetaRNN	Benign	0.26	T;T;T;T;T
MetaSVM	Benign	-0.64	T
MutationAssessor	Benign	1.0	L;.;.;.;.
PhyloP100		1.3
PrimateAI	Benign	0.33	T
PROVEAN	Benign	-1.6	N;.;.;N;.
REVEL	Uncertain	0.44
Sift	Benign	0.12	T;.;.;T;.
Sift4G	Benign	0.13	T;.;.;T;.
Polyphen		0.0	B;.;.;.;.
Vest4		0.26
MutPred		0.61		Gain of MoRF binding (P = 0.0421);.;.;.;.;
MVP		0.97
MPC		0.0037
ClinPred		0.20	T
GERP RS		0.32
Varity_R		0.29
gMVP		0.90
Mutation Taster		=39/61	disease causing

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

Other links and lift over

dbSNP: rs397508446; hg19: chr7-117243789;