NM_000492.4:c.173A>G

Variant names:

• chr7-117509042-A-G
• rs397508291
• NM_000492.4:c.173A>G

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP2 PP3_Strong

The NM_000492.4(CFTR):​c.173A>G​(p.Asp58Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000688 in 1,452,802 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. D58N) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: 7.20
• Publications: 6 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: Pathogenic. The variant received 11 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 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 chr7-117509041-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 53361.Status of the report is criteria_provided_single_submitter, 1 stars.
• 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.947

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CFTR	NM_000492.4	c.173A>G	p.Asp58Gly	missense_variant	Exon 3 of 27	ENST00000003084.11	NP_000483.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11	c.173A>G	p.Asp58Gly	missense_variant	Exon 3 of 27	1	NM_000492.4	ENSP00000003084.6

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000399 AC: 1 AN: 250818 AF XY: 0.00000738

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

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: 6.88e-7 AC: 1 AN: 1452802 Hom.: 0 Cov.: 28 AF XY: 0.00000138 AC XY: 1 AN XY: 723462

African (AFR) AF: 0.00 AC: 0 AN: 33296

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26070

East Asian (EAS) AF: 0.00 AC: 0 AN: 39610

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86082

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52994

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5742

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1104206

Other (OTH) AF: 0.00 AC: 0 AN: 60086

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Mar 29, 2024

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: CFTR c.173A>G (p.Asp58Gly) results in a non-conservative amino acid change in the encoded protein sequence. Four of four in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 250818 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.173A>G has been reported in the literature in a patient affected with congenital bilateral absence of the vas deferens (CBAVD), who carried a second pathogenic variant (Steiner_2011) and in a newborn who had positive CF screening test, but no genotype information was provided (Bozdogan_2021). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. ClinVar contains an entry for this variant (Variation ID: 53368). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Cystic fibrosis Other:1

-

ClinVar Staff, National Center for Biotechnology Information (NCBI)

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.67
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.43
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.71	D;.;.;T;.
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.96	D;D;D;D;D
M_CAP	Pathogenic	0.66	D
MetaRNN	Pathogenic	0.95	D;D;D;D;D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Uncertain	2.8	M;.;.;.;M
PhyloP100		7.2
PrimateAI	Uncertain	0.64	T
PROVEAN	Uncertain	-2.9	D;.;.;D;.
REVEL	Pathogenic	0.94
Sift	Uncertain	0.024	D;.;.;D;.
Sift4G	Uncertain	0.0030	D;.;.;D;.
Polyphen		1.0	D;.;.;.;.
Vest4		0.94
MutPred		0.81		Gain of MoRF binding (P = 0.0479);Gain of MoRF binding (P = 0.0479);Gain of MoRF binding (P = 0.0479);Gain of MoRF binding (P = 0.0479);Gain of MoRF binding (P = 0.0479);
MVP		1.0
MPC		0.0038
ClinPred		0.95	D
GERP RS		5.7
Varity_R		0.59
gMVP		0.88
Mutation Taster		=1/99	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs397508291; hg19: chr7-117149096;